Ruwaih' reported God’s Messenger as saying, “If anyone invokes a blessing on Muhammad saying, ‘O God, cause him to occupy the place near Thee on the day of resurrection’, he will be guaranteed my intercession.”
God’s Messenger went out and entering among some palm trees prostrated himself so long that I was afraid God had taken his soul. I went and looked, and he raised his head and said, “What is the matter with you? I mentioned that to him, and he told me that Gabriel had come and given him the good news that God said, “If anyone invokes one blessing on you I will bless him, and if anyone greets you I will greet him.”
Abu Huraira reported God’s Messenger as saying, “If anyone invokes a blessing on me at my grave I shall hear him, and if anyone invokes a blessing on me at a distance I shall have it conveyed to me.”