Sayyiduna Abdullah bin al-Zubayr (may Allah be pleased with him) states: Once the Prophet (peace and blessings be upon him) passed by some of his Companions. Something had come up before them that was making them laugh. The Prophet (peace and blessings be upon him) said: Are you laughing, while the mention of Paradise and Hell is among you? Then this verse was revealed concerning it: "Inform My servants that I am indeed the Forgiving, the Merciful, and that My punishment is the painful punishment."
Al-Tabarani recorded it. Its chain contains a narrator, Musa bin Ubaydah, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب التفسير / 11107