Mukhtasar Muslim (Abridged) 1788 — About one who swears by Allah

It is narrated from Sayyiduna Jundub (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: A man said, "By Allah, Allah will not forgive so-and-so." And Allah the Exalted said, "Who is he who swears that I will not forgive so-and-so? I have forgiven him, and I have rendered all the deeds (of the one who swore) null and void."