مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3873
Musnad of Abdullah bin Mas'ood
It was narrated that Abul-Ahwas said: ‘Abdullah (رضي الله عنه) used to say: Lying is not appropriate, either in earnest or in jest - on one occasion 'Affan said: in earnest, and no man should make a promise to a child and not fulfil it. He said: Verily Muhammad (ﷺ) said to us: "A man will continue to speak the truth until he is recorded with Allah as a speaker of truth, and a man will continue to tell lies until he is recorded with Allah as a liar."
Musnad Ahmad 3896Its isnad is saheeh according to the conditions of Muslim]