Sahih al-Bukhari 5285
صحيح البخاري#5285SahihNarrated Nafi`:Whenever Ibn `Umar was asked about marrying a Christian lady or a Jewess, he would say: "Allah has made it unlawful for the believers to marry ladies who ascribe partners in worship to Allah, and I do not know of a greater thing, as regards to ascribing partners in worship, etc. to Allah, than that a lady should say that Jesus is her Lord although he is just one of Allah's slaves
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 68:34