Abu al-Zanad أبو الزناد · The Book of Marriage

"The conditions that are most deserving of fulfillment are those by means of which the private parts become permitted to you."

"I met my maternal uncle who was carrying a flag (for an expedition) and I said: 'Where are you going?' He said: 'The Messenger of Allah is sending me to a man who has married his father's wife, and he has commanded me to strike his neck (kill him) and seize his wealth.'"