Sayyiduna Sahl bin Sa'd (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "Soon after me, people will offer one another condolences concerning a prophet." People began to say: What is meant by this? When the Prophet (peace and blessings be upon him) passed away, people would meet one another and offer one another condolences concerning the Prophet (peace and blessings be upon him).
Abu Ya'la and al-Tabarani recorded it, and the narrators of both are the narrators of the Sahih, except for Musa bin Ya'qub al-Zam'i, whom a group declared thiqah (trustworthy).