It is narrated from Sayyiduna Abdur Rahman bin Awf (may Allah be pleased with him), he says: I entered the mosque and when I saw the Messenger of Allah (peace and blessings be upon him) coming out of the mosque, I followed behind him, until he entered a date-palm garden and performed a prostration, and he remained in prostration for so long that I began to fear that Allah Almighty had caused him (peace and blessings be upon him) to pass away. So I came close to him (peace and blessings be upon him) to see him, and at that moment he (peace and blessings be upon him) raised his head and said: O Abdur Rahman! What has happened to you? I told him (peace and blessings be upon him) the whole matter. Upon hearing this, he (peace and blessings be upon him) said: Jibreel (peace be upon him) said to me: Shall I not give you the glad tidings that Allah Almighty has said to you that whoever sends blessings upon you, I will send mercy upon him, and whoever sends peace upon you, I will send peace upon him.