I heard the Messenger of Allah ﷺ say, "A servant continues to lie until he is recorded as a liar, or speaks the truth until he is recorded as truthful."
حدثنا عبد الرزاق أخبرنا معمر عن أبي إسحاق عن أبي الأحوص
إني سمعت رسول الله ﷺ يقول إن العبد ليكذب حتى يكتب كذابا أو يصدق حتى يكتب صديقا
Its isnad is sahih, and it is an abridgment of 3638 and 3896, see also 3845. In H, it reads "wa inni samitu" (and I heard), but the wa is not found in K, and omitting it is preferable.