Abu Hamid Al Saadi Ansari

Abu Hamid Al Saadi Ansari, a companion of the Holy Prophet and who had fought at the battle of Badr mourned the death of Uthman. He said that those who had murdered their Caliph had violated the right to be called as Muslims. He took the oath that after the death of Uthman he would never laugh and would continue to mourn his death. He fulfilled this oath, and never laughed again in life.