Umm Salamah (may Allah be pleased with her) narrated: “The Messenger of Allah (peace and blessings of Allah be upon him) said to us: ‘When you attend to the sick or dying then say only good, for indeed the angels say “Amin” to what you say.'” She said: “When Abu Salamah died I went to the Prophet and said: ‘O Messenger of Allah! Abu Salamah has died.’ He said: ‘Then say: “O Allah forgive me and him, and give me a good replacement for him.” She said: “I said that, and Allah gave a replace that was better than him: The Messenger of Allah.”
Jami’ at-Tirmidhi 977, Book 10, Hadith 13