Sayyiduna Salamah bin al-Akwa' (may Allah be pleased with him) narrates: We were with the Messenger of Allah (peace and blessings be upon him) at a funeral, and the people praised the deceased highly. The Messenger of Allah (peace and blessings be upon him) said: "It has become due." They asked: O Messenger of Allah, what has become due? He (peace and blessings be upon him) said: "The angels are Allah's witnesses in the heaven, and you are Allah's witnesses on the earth; when you bear witness, (Paradise or Hell) becomes due."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6235