Sayyiduna Anas (may Allah be pleased with him) said that a funeral passed by the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Praise him." They said: As far as we know, he loved Allah and His Messenger; that is, they praised him well. So he (peace and blessings be upon him) said: "It has become due." Then another funeral passed by him (peace and blessings be upon him), and he (peace and blessings be upon him) said: "Speak about him." The people spoke ill of him, saying that he was not good in the religion of Allah. So he (peace and blessings be upon him) said: "It has become due for him, and you are the witnesses of Allah on earth."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 7185