‘Umar ibn al-Khattaab (might Allaah be happy with him) who reported: “Du’aa’ is suspended amongst heaven and earth and none of it is actually taken up right until you deliver blessings upon your Prophet (peace and blessings click here of Allaah be on him).” (Tirmidhi, Ibn Katheer said: Its isnaad is jayyid. Classed as hasan by al-Albaani)