Qatada قتادة · The Book on Vows and Oaths

"The Prophet (ﷺ) passed by old man walking (while supported) between his two sons, so he said: 'What is the matter with this one?' They said: "O Messenger of Allah! He vowed to walk.' He said: 'Verily Allah is in no need of this person punishing himself.'" He said: "So he ordered him to ride."

"I heard the Messenger of Allah (ﷺ) saying: 'Whoever frees a believing slave, then Allah frees a limb from the Fire for each of his limbs, such that he frees his private parts in lieu of his private parts.'"

"Any Muslim man who frees a Muslim man, then it is his salvation from the Fire - each of his limbs suffices for a limb of himself. And any Muslim man that frees two Muslim women, then are his salvation from the Fire - each of their limbs suffices for a limb of himself. And any Muslim woman that frees a Muslim woman, then she is her salvation from the Fire - each of her limb suffices for a limb…