Sahih Muslim · Hadith 4381

حدثنا محمد بن رافع، حدثنا عبد الرزاق، حدثنا معمر، عن همام بن منبه، قال هذا ما حدثنا أبو هريرة، عن رسول الله صلى الله عليه وسلم فذكر أحاديث منها وقال رسول الله صلى الله عليه وسلم ‏"‏ والله لأن يلج أحدكم بيمينه في أهله آثم له عند الله من أن يعطي كفارته التي فرض الله ‏"‏ ‏.‏

Hammam b. Munabbih reported: This is what Abu Huraira reported to us from Allah's Messenger (may peace be upon him), and he narrated a hadith and (one) of them is that Allah's Messenger (may peace be upon him) said: I swear by Allah, it is more sinful in Allah's sight for one of you to persist in an oath regarding his family than payment of its expiation which Allah has imposed upon him (for breaking the oath).

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).