Sunan Abi Dawud — Wills (Kitab Al-Wasaya)

Mus’ab b. ‘Umar was killed at the battle of Uhud, and for him only a coarse cloth would be found as shroud. When we covered his head, his feet showed, and when we covered his feet, his head showed. So the Messenger of Allah (ﷺ) said: Cover his head with it (cloth), and put some rushes over his feet.

A woman made a voyage and vowed that she would fast one month if Allah made her reach her destination with peace and security. Allah made her reach her destination with security but she died before she could fast. Her daughter or sister (the narrator doubted) came to the Messenger of Allah (ﷺ). So he commanded to fast on her behalf.

“I was sitting with the Prophet when a woman came to him and said: ‘O Messenger of Allah! I gave a slave girl to my mother in charity and she died.’ He said: ‘Your reward is already established, and your right to inherit her has returned it (that Sadaqah) to you.’ She said: ‘O Messenger of Allah! There was a month of fasting due on her, shall I perform the fast for her?’ He said: ‘Fast on her behalf.’ She said: ‘O Messenger of Allah! She never performed Hajj, shall I perform Hajj for her?’ He said: ‘Yes, perform Hajj on her behalf.'”

“A woman from Khath’am said: ‘O Messenger of Allah! My father has lived until Allah has made Hajj obligatory, and he is an elderly man who is not able to sit on the back of a camel.’ So he (pbuh) said: ‘Perform Hajj for him.'”

“I took an oath by Lat and ‘Uzza. The Messenger of Allah (ﷺ) said : ‘Say: “La ilaha illallah wahdahu la sharika lahu” (None has the right to be worshipped but Allah alone, with no partner or associate),” then spit toward your left three times, and seek refuge with Allah, and do not do that again.”‘

The Messenger of Allah (ﷺ) forbade selling the right of inheritance, or giving it as a gift.