‘Abd ar-Rahman b. ‘Auf said: 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.” Ahmad transmitted it.