Durood_Ibraaheemi

Allahumma salli ala muhammadiw wa ala aali muhammadin kamaa sallaita ala ibrahima wa ala aali ibrahima innaka hamidum majid.
Allahumma baarik ala muhammadiw wa ala aali muhammadin kamaa baarakta ala ibrahima wa ala aali ibrahima innaka hamidum majid.

“O Allah, let Your Blessings come upon Muhammad and the family of Muhammad, as you have blessed Ibrahim and his family. Truly, You are Praiseworthy and Glorious. Allah, bless Muhammad and the family of Muhammad, as you have blessed Ibrahim and his family. Truly, You are Praiseworthy and Glorious”.

The famous companion of the Prophet (Sallal Laahu Alaihi Wasallim), Hazrat Ka’ab bin Ujrah (radi Allahu anhu), narrates that once it was enquired from Sayyiduna Rasoolullah (Sallal Laahu Alaihi Wasallim) as to how blessings should be sent to him. The Prophet (Sallal Laahu Alaihi Wasallim) replied that the blessings be said in the manner (it has been mentioned) above, that is, Durood-e-Ibrahimi.

Source: http://www.islamicacademy.org/html/Articles/English/Excellence_in_Durood_Sharif_2.htm