Ma'bad narrates this about the Prophet Muhammad (peace be upon him): Once he (peace be upon him) was leading the prayer, a blind man came and fell into a pit, so some people laughed, to the extent that they burst out laughing. When he (peace be upon him) finished the prayer, the Prophet Muhammad (peace be upon him) said: "Whoever among you has laughed out loud, let him perform ablution and repeat the prayer."
Hadith Referenceسنن الدارقطني / كتاب الطهارة / 622
Hadith Takhrij«أخرجه الدارقطني فى ((سننه)) برقم: 622، 623»