Sunan Ibn Majah · Hadith 2633
The Chapters on Legal Punishments - كتاب الحدود
حدثنا أبو بكر بن أبي شيبة، حدثنا أبو أسامة، عن بهز بن حكيم، عن أبيه، عن جده، قال قال رسول الله صلى الله عليه وسلم " لا يقبل الله من مشرك أشرك بعد ما أسلم عملا حتى يفارق المشركين إلى المسلمين " .
It was narrated from Bahz bin Hakim, from his father, from his grandfather that the Messenger of Allah (ﷺ) said: “Allah (SWT) will not accept any good deed from a polytheist who committed polytheism after having become Muslim, until he leaves the polytheists and joins the Muslims.”
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).