Why do Muslims Send Prayers on the Prophet Mohammed?

You can read about it here (I tried to make it more readable):

Of the greatest blessings that Allah (ta’ala) has given to mankind is sending the Prophet (sal Allahu alayhi wa sallam) as our guide and the Qur’an as our Book.

With the exception of Muhammad (sal Allahu alayhi wa sallam), every Prophet and Messenger sent by Allah (azza wa jal) was sent to a specific nation for a specific time period. Allah (ta’ala) chose Muhammad (sal Allahu alayhi wa sallam) as the Messenger for all the worlds and raised his status and mention among all of mankind.

Allah (ta’ala) describes this bounty that He gave to the Prophet (sal Allahu alayhi wa sallam) in the Qur’an,

وَرَفَعْنَا لَكَ ذِكْرَكَ

and We have raised for you your mention. (94:4)

We bear witness five times a day that he is the Messenger of Allah, we send peace upon him during our prayers, we open our gatherings with his mention after the mention of Allah (azza wa jal) and we ask Allah to bless him before we make a duaa [prayer request]. All of these acts show that we bear witness that he (sal Allahu alayhi wa sallam) delivered the message. Bearing witness that he delivered the message necessitates his love, his obedience and sending salah when he is mentioned, sal Allahu alayhi wa sallam.

Allah (azza wa jal) says,

إِنَّ اللَّهَ وَمَلَائِكَتَهُ يُصَلُّونَ عَلَى النَّبِيِّ يَا أَيُّهَا الَّذِينَ آمَنُوا صَلُّوا عَلَيْهِ وَسَلِّمُوا تَسْلِيمًا

Allah and His angels send blessings on the Prophet: O you that believe! Send your blessings on him, and salute him with all respect. (33:56)

The ayaat in the Qur’an that commands the believers to do good deeds or refrain from evil actions begins with “Ya ayyuhal latheena aamano”, “O you who have believed” however this ayah does not begin in this way. Rather, Allah (ta’ala) mentions that He and His Angels send blessings and greetings on the Prophet (sal Allahu alayhi wa sallam) first before calling the Believers to follow. Allah (subhanahu wa ta’ala) calls the believers, because of your emaan [faith], send salah and salaam on the Messenger. The Scholars of tafseer [interpretation] state that this is to show the honorable and elevated status of the Prophet (sal Allahu alayhi wa sallam) as well as to show the honor in the act of sending salah on him. If Allah and His Angels do this action, it should motivate the Believers to do so as well…

Why do we Send Salawat [Prayers] on the Prophet?

If a close relative of ours passed away, such as a parent or a sibling, we would vehemently ask Allah to forgive them, to grant them security, and to enter them into Jannah [paradise]. The Believers are those who love the Prophet (sal Allahu alayhi wa sallam) more than their family, wealth and their own selves so just as we would ask Allah to forgive and bless our relative, we should send prayers upon our Messenger (sal Allahu alayhi wa sallam) who, by the bounty and mercy of Allah, has taught us our faith. Allah azza wa jal says,

هُوَ الَّذِي بَعَثَ فِي الْأُمِّيِّينَ رَسُولًا مِّنْهُمْ يَتْلُو عَلَيْهِمْ آيَاتِهِ وَيُزَكِّيهِمْ وَيُعَلِّمُهُمُ الْكِتَابَ وَالْحِكْمَةَ وَإِن كَانُوا مِن قَبْلُ لَفِي ضَلَالٍ مُّبِينٍ وَآخَرِينَ مِنْهُمْ لَمَّا يَلْحَقُوا بِهِمْ وَهُوَ الْعَزِيزُ الْحَكِيمُ ذَ‌ٰلِكَ فَضْلُ اللَّهِ يُؤْتِيهِ مَن يَشَاءُ وَاللَّهُ ذُو الْفَضْلِ الْعَظِيمِ

It is He Who has sent amongst the unlettered a Messenger from among themselves, to rehearse to them His Signs, to purify them, and to teach them the Book and Wisdom (Sunnah),- although they had been, before, in manifest error;-As well as (to confer all these benefits upon) others of them, who have not already joined them: And He is exalted in Might, Wise. Such is the Bounty of Allah, which He bestows on whom He wills: and Allah is the Lord of the highest bounty. [62:2-4]

We send salawat on the Prophet (sal Allahu alayhi wa sallam) to acknowledge the great blessing that Allah has given us by sending the Messenger to us. Just as prayer is a manifestation of our love, gratitude and obedience to Allah (azza wa jal), sending salawat on the Prophet (sal Allahu alayhi wa sallam) shows our love for him, our respect for him, and our obedience to him.

We must also remember that Rasul [the Messenger of] Allah (sal Allahu alayhi wa sallam) was only a man who does not possess any power to harm or benefit us. Many from amongst our Ummah have taken their love of the Prophet (sal Allahu alayhi wa sallam) to an extreme that is not only forbidden in our religion, but does the exact opposite of their intended goal. Worship is exclusive for Allah (azza wa jal) and obeying and loving the Prophet (sal Allahu alayhi wa sallam) falls under the worship of Allah…

Read the whole thing, especially the “Benefits and Virtues of Salawat.”