Sayyiduna Abu Musa al-Ash'ari (may Allah be pleased with him) says: We offered a funeral prayer behind the Prophet (peace and blessings be upon him), and he gave the salam to his right and to his left.
Al-Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat. Its chain contains Khalid bin Nafi' al-Ash'ari, whom Abu Zur'ah declared da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الجنائز / 4170