Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Allah has commanded us to send blessings on the Prophet Muhammad (peace and blessing be upon him) He said: {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]. Imam Bukhari narrated in explanation of this verse that Ka'b bin Ujrah said, (اللهم صل على محمد وعلى آل محمد، كما صليت على آل إبراهيم، إنك حميد مجيد. اللهم بارك على محمد وعلى آل محمد، كما باركت على آل إبراهيم، إنك حميد مجيد) "We asked Allah's Apostle saying, 'O Allah's Apostle! How should one (ask Allah to) send blessings on you, the members of the family, for Allah has taught us how to salute you (in the prayer)?' He said, 'say: O Allah! Send Your Mercy on Muhammad and on the family of Muhammad, as You sent Your Mercy on Abraham and on the family of Abraham, for You are the Most Praiseworthy, the Most Glorious. O Allah! Send Your Blessings on Muhammad and the family of Muhammad, as You sent your Blessings on Abraham and on the family of Abraham, for You are the Most Praiseworthy, the Most Glorious.' It is narrated in another narration from Abu Humaid as-Saidi he said: (اللهم صل على محمد عبدك وعلى آله وأزواجه وذريته كما صليت على إبراهيم وآل إبراهيم، وبارك على محمد وآله وأزواجه وذريته كما باركت على إبراهيم وآل إبراهيم إنك حميد مجيد). The people asked, "O Allah's Apostle! How shall we (ask Allah to) send blessings on you?" Allah's Apostle replied, "Say: O Allah! Send Your Mercy on Muhammad and on his wives and on his offspring, as You sent Your Mercy on Abraham's family; and send Your Blessings on Muhammad and on his offspring, as You sent Your Blessings on Abraham's family, for You are the Most Praiseworthy, the Most Glorious." All these forms are correct so you may use one of them in your prayer. There are many times one may send blessings on the Prophet some of them are as below: 1. When the Prophet is mentioned it is desirable to send blessings on him. Some Scholars believe that sending blessings is compulsory when the Prophet is mentioned. 2. Following the Adhan. The Prophet said: "When you hear the Mu'adhdhin, repeat what he says, then invoke a blessing on me." 3. In the night or day of the Friday. The Prophet said: "Increase sending blessing on me in the day and night of the Friday. Whoever does so I will be witness or intercede for him the Day of Judgment. 4. In the beginning and ending of "Du'a" invocation. Imam Nawawi said: "It is desirable to begin and end all invocations by praise of Allah and asking blessings for the Prophet as the Muslim Scholars have agreed upon it. There are many sayings from the good ancestors to support this view point". 5. It is desirable to send the blessings ten times on the Prophet during the invocations that are recited in morning and evening. The Prophet said: "Whoever sends blessings on me ten times in morning and ten times in evening, he will receive my intercession on the Day of Judgment. This is narrated from a sound chain. 6. It is Sunnah to send the blessings on the Prophet after the second Takbeer in funeral prayer. It is desirable to use the words mentioned above that is Salat al-Ibrahimi. 7. Sending blessings on the Prophet also requested in the last Tashhud. Some Scholars even believe that it is an obligation and the prayer becomes null if one leaves it. 8. Sending blessings on the Prophet also desirable at the end of a meeting. The Prophet said: "A gathering in which there is no mention of Allah, the Exalted and High, nor any invoking of blessing for their Prophet, will be afflicted with remorse. If Allah Wills He might punish them and if He Wills He might forgive them. Allah knows best.