One-fifth of Booty to the Cause of Allah (Khumus)

Bukhari :: Book 4 :: Volume 53 :: Hadith 396

Narrated Um Hani:

the daughter of Abu Talib: I went to Allah's Apostle on the day of the conquest of Mecca and found him taking a bath, and his daughter Fatima was screening him. I greeted him and he asked, "Who is that?" I said, "I, Um Hani bint Abi Talib." He said, "Welcome, O Um Hani." When he had finished his bath, he stood up and offered eight Rakat while dressed in one garment. I said, "O Allah's Apostle! My brother 'Ali has declared that he will kill a man to whom I have granted asylum. The man is so and-so bin Hubaira." Allah's Apostle said, "O Um Hani! We will grant asylum to the one whom you have granted asylum." (Um Hani said, "That (visit) took place in the Duha (i.e. forenoon)).