Sending salutations on the Prophet (peace be upon him) is a form of worship. The Qur’an says : “Allah sends His Salat (Graces, Honors, Blessings, Mercy) on the Prophet (peace be upon him), and also His angels (ask Allah to bless and forgive him). O you who believe! Send your Salat on (ask Allah to bless) him (Muhammad) and (you should) greet (salute) him with the Islamic way of greeting (salutation i.e. As-Salamu Alaikum). (33:56)
In this verse, Muslims have been commanded two things; sallu ‘alaihi, meaning to be inclined to somebody, to attend to him with love and to bend over him, and sallimu taslima, meaning to attend to him with love and to praise somebody and to pray for somebody. When the word yusalli is used with regard to Allah, it cannot mean that Allah should pray to someone else but that He conveys blessings on someone. But when this word is used for His servants whether angels or men, it contains a sense of love, praise and a prayer for mercy. Therefore, the meaning of the command to the believers sallu ‘allaihi (upon the Prophet) is to ask Allah to confer blessings upon him.
The Prophet (pbuh) said: “When a Muslim asks one blessing for me, Allah sends 10 blessings upon him, and forgives his sins and raises his rank 10 degrees. In another Hadith the Prophet (pbuh) said: “When a person sends one salutation on me the angels send 70 mercies upon him.”
Ubayy Bin Ka’ab narrated: “O Prophet of Allah I spend one-third of my supplication time in sending salutations upon you.” The Prophet (pbuh) replied, “If you increase it would be better for you.” So Ubayy Bin Ka’ab said, “If I make two-third of my supplication time in sending salutation upon you?” The Prophet (pbuh) replied, “If you increase it will be better for you.” So Ubayy Bin Ka’ab said, “Then I will spend the entire time of my supplication in sending salutations upon you.” The Prophet (peace be upon him) replied, “Then Allah will be sufficient for you for this world as well as the next.”
Sending salutations on the Prophet removes many problems for us in this world as well as the next. Ka’ab Bin ‘Ujrah reported: “The Prophet (pbuh) came to us and we asked him, “O Messenger of Allah we already know how to say salaam to you but how should we supplicate for you? ” He said: “Exalt the mention of Muhammad and the family of Muhammad as You exalted the family of Ibrahim. You are the Praised One and Glorious. O Allah, bless Muhammad and the family of Muhammad as You blessed the family of Ibrahim. You are the Praised One and the Glorious. (Bukhari and Muslim)
Ibn Masud reported the Messenger of Allah (pbuh) as saying: “The people who will be nearest to me on the Day of Resurrection will be those who supplicate Allah most often for me.” (Al-Tirmidhi-Hasan)
And Anas reported, “The best of your days is Friday, “so supplicate Allah more often for me in it, for your supplications will be showed to me. “He was asked, “O Messenger of Allah, How will our blessings be displayed to you when your decayed body will have mixed with the earth?” The Prophet (pbuh) replied: “Allah has prohibited the earth from consuming the bodies of the Prophets. “The Messenger of Allah (pbuh) said: “The miser is the one in whose presence I am mentioned but he does not supplicate for me.”