Bismillahir Rehmanir Raheem
It is completely within the Shari'ah to recite Salutations and Blessings upon Allah's Messenger (sallal laahu alaihi wasallam) as is evident in the following Quranic verse: "Undoubtedly, Allah and His Angels send blessings on the Prophet (the Communicator of Unseen News), O you who believe! Send upon him blessings and salute him fully well in abundance". (Surah al-Ahzab, Verse 56)
Here, in the above verse, Allah Ta?ala at the very outset attributed Salawat (recital of blessings) on our Beloved Nabi Hazrat Muhammad (sallal laahu alaihi wasallam), first to Himself (Sunnat-i-Ilaahi), then to His Angels (Sunnat-i-Malaa'ika), and after this enjoined on the Muslims (Sunnat-i-Mu'mineen) to do the same.
It is stated in the commentary of the Qur'aan, "Tafseer-i-Rooh al-Bayaan": "Some 'Ulama are of the opinion that the meaning of Allah's blessing is to raise Hazrat Muhammad Mustapha (sallal laahu alaihi wasallam) to Maqaam-i-Mahmood (Glorious Station), the place from where he will intercede to Almighty Allah on behalf of his Ummat; the Angels' blessing means their prayer for enhancing the position of Hazrat Muhammad Mustapha (sallal laahu alaihi wasallam) and beseeching forgiveness for his followers. Blessings on the path of the believers means to obey, love and eulogize him."
The honour and reverance shown to Hazrat Muhammad (sallal laahu alaihi wasallam) is of a much greater degree than shown to Hazrat Adam (alaihis salaam) to whom only Angels were made to bow down (in honour). For in honouring Hazrat Muhammad Mustapha (sallal laahu alaihi wasallam) Allah Ta?ala has also attributed it to Himself, whereas in the case of Hazrat Adam (alaihis salaam) Allah Ta?ala asked only the Angels to show honour.
The Holy Prophet (sallal laahu alaihi wasallam) said: "Increase your recitation of DUROOD on me on Friday because on this day Angels present themselves to me. There is no servant of Allah who recites SALUTATIONS upon me, except that his voice reaches me from wherever he is". The Companions asked even after your departure? He replied, "Yes after my departure too, because Allah has made it Haraam upon the earth to consume the bodies of the Prophets". (Jila-ul Ifhaam)
"On Fridays recite the Salawat for me repeatedly! The Salawat will be conveyed to me." (Ibn Habbaan, Ibn Majah) When it was asked whether the Salawat would be conveyed to him after his Wisaal also, the Prophet (sallal laahu alaihi wasallam) answered, "Soil does not rot Prophets' bodies. Whenever a Muslim says the Salawat for me, an Angel informs me of it and says, 'So-and-so's son, so-and-so of your Ummah sent his Salaam and prayed for you.'"
Allah's Messenger (sallal laahu alaihi wasallam) came out and met Hazrat Abu Talha (radi Allahu anhu). The latter rose and went to him saying: "My father and mother be sacrificed for you, O Messenger of Allah! I see joy and delight in your countenance?" The Prophet (sallallahu 'alaihi wasallam) said: "Yes, for Gabriel has just come to me saying: ?O Muhammad, whoever among your Community invokes blessings upon you once, Allah records for Him ten meritorious deeds, erases from his register ten evil deeds, and raises him ten degrees because of it?." (al-Sakhawi, al-Qawl al-Badi)
The Holy Prophet (sallal laahu alaihi wasallam) said: "Invoke blessings upon me abundantly on Friday because it is a day that is (particularly) witnessed and the Angels witness it (abundantly). As soon as a person invokes blessings on me his invocation is shown to me until he ends it." Hazrat Abu al-Darda' (radi Allahu anhu) said: "Even after (your) death?" The Prophet (sallal laahu alaihi wasallam) replied: "Verily, Allah has forbidden the earth to consume the bodies of Prophets." (Ibn Majah)
The Holy Prophet (sallal laahu alaihi wasallam) says in a Hadith, "Definitely there are many Angels of Allah that sojourn the earth and bring the Salaam of my Ummat to me". (Nisaai; Ibn Habban)
Hazrat 'Abd ar-Rahman bin 'Auf (radi Allahu anhu) says that one day the Holy Prophet (sallal laahu alaihi wasallam) came and entered a date garden. There he performed a very long prostration. Hazrat 'Abd ar-Rahman (radi Allahu anhu) feared that Allah Ta?ala had caused him to leave this world. He drew close to him and began to look at him. The Holy Prophet (sallal laahu alaihi wasallam) raised his holy head from the prostration and asked what had happened to him. He disclosed his fear to him. At this, the Holy Prophet (sallal laahu alaihi wasallam) said that Hazrat Jibra'il (alaihis salaam) asked whether he should not give him glad tidings that Allah Ta?ala said that He would send blessings to the person who recited the Holy Qur'an on him and peace and security to the person who bade Salutations to him. (Ahmad)
These are just a few Ahaadith. It is established beyond any doubt that the recitation of Salawat and Salaam has its origin in the Quran and Hadith.
Some people say that it is wrong to send Salaam to the Prophet (sallal laahu alaihi wasallam) in the form of a Naat (Verses in Praise of the Prophet).
Rasoolullah (sallal laahu alaihi wasallam) had amongst his Ashaab, poets who used to refute the slanders of the enemies and eulogize (praise) the Holy Prophet (sallal laahu alaihi wasallam). Rasoolullah (sallal laahu alaihi wasallam) liked the poetry of Hazrat Hassan ibn Thabit (radi Allahu anhu) the most. He offered the Mimbar to Hazrat Hassan (radi Allahu anhu), who would censure the enemies and praise Rasoolullah (sallal laahu alaihi wasallam) on the Mimbar. Rasoolullah (sallal laahu alaihi wasallam) on hearing the poetry of Hazrat Hassan (radi Allahu anhu) prayed, "Allahumma ayyidhu bi rooh hil Qudus!" (O Allah, let the holy spirit (Jibrael) be his helper (in recitation) (Mishkaat)
When Rasoolullah (sallal laahu alaihi wasallam) made Hijra and entered Madina, the people sang out, "Tala`a al-badru `alayna, Min thaniyyat al-wada`, Wajaba al-shukru `alayna, Ma da`a lillahi da`". Ulama from time immemorial have been writing and reciting Naat and Qasaa'id in Praise of Rasoolullah (sallal laahu alaihi wasallam) in a variety of languages.
Some people say that it is wrong to send Salawat and Salaam because those who read Salaam put a chair in the gathering and say that the Prophet (sallal laahu alaihi wasallam) is sitting on the chair whilst the Salaam is being read. The curse of Allah is on those liars! No true Muslim has ever done such a thing.