Mukhtasar Bukhari (Abridged) 1549 — Virtues of Hasan and Husayn (RA)

Narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that a man from among the people of Iraq asked him: "If a person in the state of Ihram kills a fly?" So Sayyiduna Ibn Umar (may Allah be pleased with them both) said: "The people of Iraq ask about killing a fly, even though they killed the grandson of the Noble Prophet (peace and blessings of Allah be upon him), about whom the Noble Prophet (peace and blessings of Allah be upon him) said: 'These two are my flowers in this world.'"