مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4159
Musnad of Abdullah bin Mas'ood
It was narrated from ‘Abdullah (رضي الله عنه) from the Prophet (ﷺ) that he said: "A man may continue to tell the truth and endeavour to tell the truth until he is recorded as a speaker of truth. And a man may continue to tell lies and endeavour to tell lies, until he is recorded as a liar.”
Musnad Ahmad 4187Its isnad is saheeh, al-Bukhari (6094) and Muslim (2607)]