Musnad Ahmad Hadith 18061

It is narrated from Ka'b bin Murrah (may Allah be pleased with him) that I heard the Prophet (ﷺ) say: Whoever frees a Muslim, it becomes a means of deliverance for him from Hell, and for every limb of the slave, a limb of the one who frees him is set free. And whoever frees two Muslim women, both of them become a means of deliverance for him from Hell, and for every limb of theirs, a limb of the one who frees them is set free from Hell. And if a woman frees a Muslim woman, she becomes a means of deliverance for her from Hell, and for every limb of the slave-girl, a limb of hers is set free from Hell. And the Prophet (ﷺ) invoked a curse against the tribe of Mudar. I came to the presence of the Messenger and said: O Messenger of Allah (ﷺ), Allah has helped you, granted you, accepted your supplication, your people are being destroyed, so supplicate to Allah for them. The Prophet (ﷺ) turned his face away. I repeated my words, then the Prophet (ﷺ) said: O Allah! Give us a rain that will abundantly water us, fill the earth with water, be plentiful, not delayed, beneficial, not harmful. After this supplication, the Friday prayer had not yet taken place when the rain began.