Sayyiduna Anas (may Allah be pleased with him) said: A funeral passed by the Prophet (peace and blessings be upon him) and the deceased was praised, so he (peace and blessings be upon him) said: "It has become due." Another funeral passed and the deceased was spoken of badly, so he (peace and blessings be upon him) said: "It has become due." It was said to him (peace and blessings be upon him): What has become due for both? He (peace and blessings be upon him) said: "The believers are Allah's witnesses on the earth."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20389