Sayyiduna Anas bin Malik (may Allah be pleased with him) said that people passed by him (peace and blessings be upon him) with a funeral and praised the deceased well, so the Messenger of Allah (peace and blessings be upon him) said: "Wajabat (It has become due)." Then another funeral passed and its evil was mentioned, so he (peace and blessings be upon him) said: "Wajabat (It has become due)." Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said: O Messenger of Allah, what has become due? He (peace and blessings be upon him) said: "The one whose good you mentioned, Paradise has become due for him; and the one whose evil you mentioned, the Fire has become due for him. And you are the witnesses of Allah on earth."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 7184