Ibn Abi Nu'm said, "I was with Ibn 'Umar when a man asked him about the blood of gnats. He asked, 'Where are you from?' 'From the people of Iraq,' he replied. He said, 'Look at this man! He asks about the blood of gnats when they murdered the grandson of the Prophet, may Allah bless him and grant him peace! I heard the Prophet, may Allah bless him and grant him peace, say, 'They are my sweet basil in this world.'"