Throughout time, the opponents of the prophets, because of their incapacity at denying the forceful arguments presented, reckoned that the only way in which they could tone down their ever increasing influence on the masses was to besmear their character and integrity
Ezek21:5"O Lord God, they say of me, 'Is he not an inventor of parables?".Among their attacks, they would twist their prophecies publicly and deride the revelations
Ezek33:30-31"the members of your people who talk about you beside the walls and in the entrances of the houses..And they will come to you as a public gathering, and they will sit before you as My people, and they will hear your words but not fulfill them; instead they make them into jokes with their mouth; their heart goes after their gain".These talks did cause them grief and sorrow however they were relieved knowing that God is their witness and, along with the angels, constantly showers them with blessings.
Concerning the prophet who is the first and foremost in submission, obedience and devotion to Allah 6:14,39:11-12 we are told that
In ancient times, the practice of necromancy consisted in conversing with the dead, inquiring and receiving answers from them through dreams or while awake. The occultist would lie in graveyards, dig up bones and speak to the dead person seeking answers for future matters. The practice seems to have been widespread among the Israelites in the time of Isaiah (Isa8:19). Of course all this is far from the Islamic prayer in which Muslims ask God to bless the prophet, their own selves and all the righteous present or not.
33:56"Allah and His angels send blessing/yusallun upon the Prophet".Divine blessings are showered on him as was done with past prophets and messengers 37:113 such as Ibrahim, Ismail, Ishaq, Yaqoub, Musa or Ilyas. The Quran tells us to praise, these eminent personalities, remember their exalted status among later generations 37:108,119,129,38:45-49. Muslims consequently remember them along with all the righteous in the daily prayers. To add to the sense of appreciation from Allah, yusallun is in the present form, which conveys the sense of perpetuity and continuity of a state in classical Arabic. This makes the prophet constantly under Allah's blessings.
When Allah and His angels yusallun on the prophet just like Allah and His angels yusallun on the believers 2:157,33:42-43,40:7-9 it does not mean the ritual salaat of worship. Neither does the word yuqimu precede it 4:103 nor does it say ila/to or for, rather aala/upon. There is no hint at anyone praying to any other than Allah, much less of Allah praying to someone else. Confusing doctrines such as these are found in Trinitarianism, with separate divine entities contingent on oneanother, praying, begging, receiving things, and needing permission from eachother.
Salat stems from s-l-y. It is used in concrete for the horses in a race whose heads connect with the lower back of the one in the front. In the vivid conceptual language of the Arabs, it became a metaphor for closeness in connection, reaching of a goal. All these apply to the ritual salat to God. The goal is Allah with whom a person connects through worship of Him exclusively, the One to Whom all praise is due in the Heavens and Earth and in the Hereafter 34:1. When the angels do salat upon (not to) the believers, the goal are the believers with whom the angels connect by worshipping Allah so that He communicates His blessings on them. At no point are the believers worshipped by the angels, although they are intended in the angels' worship to Allah. Similarly God tells the believers to do salat on their prophet 33:56. Their goal is the prophet and they connect with him by worshipping Allah so that He communicates His blessings on him. Never is the prophet worshipped, intentionally or not.
The prophet Muhammad is commanded to reciprocate, and do salat on the people 9:103 as it will give them a sense of relief. Never did the prophet worship any believer.
Finally when Allah does salat upon (not to) someone, such as the prophet, then similarly Allah's goal is the prophet with whom He connects, not by worshiping him, but by communicating His blessings on him. Salat is not equal to worship but may include it. Salat is a connection with a goal. The type of connection and goal are different depending on the sender and receiver. Between created entities their goal is to connect with oneanother, never through worshipping one another, rather through worshipping Allah that he might send his blessings. When God is the sender of salat unto His creation, He establishes connection with it not by worshipping it or any other entity, but by blessing it with His guidance 33:43.
Had the action of Allah doing salat involve the worship of another entity so that it might bless another, then the result would instead be for that worshipped entity itself to cause the blessing. But the guidance comes from Allah alone
"He it is Who does salat upon you, and His angels that He might bring you forth from the darkesses into the light, and He is merciful to those who put their trust in Him".
Again, when someone does salat on another who isnt worthy, he will not receive Allah's mercy. This shows again, the implication of doing salat is to communicate something from Allah upon another, never from another divine entity. Consequently the prophet is told that he should not do salat (yusalli) on the disbelievers when they die because they have been forbidden from Allah's forgiveness 9:80,84.
The result of Allah doing salah upon someone is therefore to bestow goodness from Himself on the person. But because mercy best encapsulates goodness from Allah, we find in the Quran and ahadith the salah from Allah equated with mercy from Himself
2:157"Those are the ones upon whom are salawaat from their Lord and mercy. And it is those who are the [rightly] guided".
The WAW which is translated in general as AND, also often means inclusion of a particular entity within the general more encompassing entity. The purpose is to highlight one aspect of the more encompassing concept. Salah from Allah therefore includes mercy, as well as other good things one may think of. Al Bukhari reports from Sufyan Ath-Thawri that
"The Salah of the Lord is mercy".
He also reports that
"Allah's Salah is His praising him".
The following narration, although weak also explains what is meant by the salah of Allah
“The Israelites said to Musa: Does your Lord pray? Musa said: Fear Allah, O Sons of Israel! Allah said: O Musa! What did your people say? Musa said: O my Lord, You already know? They said: Does your Lord pray? Allah said: Tell them My prayer for My servants is that My Mercy should precede My Anger. If it were not so, I would have destroyed them.”
In another equally weak narration
“He (the Prophet PBUH) asked: ‘What is His Salah?’. He (Gabriel) said, He says: ‘Perfect, Most High is the Lord of the angels and the Spirit, My Mercy overwhelms my wrath.'”
The same reasoning applies to the greeting of "salaam" which is a supplication to Allah, that He might bestow peace on another. When Allah in turn greets with "salaam" He is bestowing peace from Himself upon another
11:48"It was said: O Nuh! descend with peace from Us".
To the dwellers of heaven, their peace will manifest by Allah appeasing their hearts to the fullest
5:45-7"in the midst of gardens and fountains. Enter them in peace, secure. And We will root out whatever of rancor is in their breasts".
No entity obtains salaam unless shown the way by Allah
20:47,5:16"God shows unto all that seek His goodly acceptance the paths leading to peace/salaam and, by His grace, brings them out of the depths of darkness into the light and guides them onto a straight way".
In sura yasin, when someone receives the word of peace from Allah, the verse ends by stressing Allah's mercy, because it is only through His mercy that peace enters the hearts of the believers 36:58.
A comparable terminology is in regards to the concept of intercession. Speaking of the hereafter, the prophet said
"Then the prophets and Angels and the believers will intercede, and (last of all) the Almighty (Allah) will say, 'Now remains My Intercession. He will then hold a handful of the Fire from which He will take out some people whose bodies have been burnt, and they will be thrown into a river at the entrance of Paradise, called the water of life. They will grow on its banks, as a seed carried by the torrent grows. You have noticed how it grows beside a rock or beside a tree, and how the side facing the sun is usually green while the side facing the shade is white. Those people will come out (of the River of Life) like pearls, and they will have (golden) necklaces, and then they will enter Paradise whereupon the people of Paradise will say, 'These are the people emancipated by the Beneficent. He has admitted them into Paradise without them having done any good deeds and without sending forth any good (for themselves).' Then it will be said to them, 'For you is what you have seen and its equivalent as well.'"
The word for intercession here is Shafa'a which is linguistically different than tawasul. Shafaa of Allah is not a pleading action to another God. The people of paradise here recognize that it is Allah Himself who caused those people to enter heaven. This will be the ultimate act of Mercy, hence the people of paradise referring to Allah as al Rahman. Those sinners for whom Allah did not allow any intercession will ultimately be honoured by the shafa'a of Allah Himself, once their sins have been cleansed in the hellfire. The shafaa of Allah is to come between the person and his punishment, then doing as He pleases and deems fit; which is to take the person out of hellfire and place him in paradise. Shafaa between human beings entails that someone, allowed by Allah, comes between Allah and another person so as to honour and uplift that person.
By now it has been made clear, salat is an action that does not always include worship, neither by the sender nor to the receiver of the salat. Further it is not exclusive to the prophet Muhammad. He is a nabi like all the others between whom Muslims should never discriminate 3:84. Nor is the command to salla reserved for the prophets; it is a universal and recommended action between all believers equally.
A similar terminology is God's repeated command that the believers should "aminu" in the prophet. Although often translated "believe", that rendition doesnt do full justice to the word which literally means to "make oneself safe in an entity" ie fully trust it. So the believers are to fully trust their prophet and feel safe in him just as he does in them 9:61.
Finally, the tashahhud during prayer mentions the prophet, but also oneself and all righteous servants of God, present or not. The prophet said
"When you send Salam on me, send Salam on all the Messengers, for I am one of the Messengers".
None of those individuals are glorified, nothing is expected from them, nor are they believed to be able to perceive these words of prayers directly. Calling upon them emphasizes their presence in one's mind. At all moments, God is glorified and asked to send His peace and mercy on them. Talking in this manner to someone absent and beyond sensory perception, dead or alive, doesnt deify the person. This is done very frequently in everyday life. Nothing is expected in return from that person nor is he thought to directly perceive what is said. This is in stark contrast with the worship of saintly personalities as is widely practiced in Catholicism. Saints hear the prayers directly, and are expected to fulfil particular needs of the devotees, either through their own power, or through intercession with a higher stationed entity.
In Islam, dead people, believers and disbelievers alike, are alive in an intermediary realm until the day of resurrection 2:154,3:169,40:46. An inviolable barrier is placed between us and them preventing any type of interaction between these parallel realms 23:99-100.
The only manner for those alive in that realm to know of things happening in our world, is indirectly. If God decides to convey to them information from the present world. For instance the prophet said
"‘Allah has angels who travel around on Earth conveying to me the Salams of my Ummah".
In addition, there are deeds they have left behind that can benefit them. Things such as an ongoing benevolent action that benefit people down the line (like planting a tree or digging a well) or beneficial knowledge, or a righteous child who will pray for his dead parent.
This is a major Quranic theme, exemplified by the prophet and stressed upon the Muslims; that the best, most beneficial deeds are those that have God and one's fellow human being as motivating factor, no matter how insignificant
"Allah's Messenger said, "While a man was on the way, he found a thorny branch of a tree there on the way and removed it. Allah thanked him for that deed and forgave him".
However the deceased wont be aware of those deeds while they are performed in his name, including prayers, until they are raised
"A man's status will be raised in pradise and he will ask, How did I get here? He will be told, By your sons' duaa for forgiveness for you".