Musnad Ahmad 1662

It was narrated that "Abdur-Rahman bin ‘Awf said: The Messenger of Allah (ﷺ) went out and I followed him until he entered a grove of palm trees. Then he prostrated and remained in prostration for a long time, until I was afraid that Allah had taken his soul. I went to look, and he raised his head and said: "What is the matter, O" Abdur-Rahman?" I told him what it was and he said: "Jibreel () said to me: "Shall I not tell you the glad tidings? Allah, may He be glorified and exalted, says to you: “Whoever sends blessings upon you, I shall send blessings upon him, and whoever sends salams upon you, I shall send salams upon him.”