The title says it all. A chapter reference, quote, and translation would be appreciated
To answer your question directly: the already cited Qur’anic passage 33:40 in the only aya in the Qur’an that uses the term “seal of the prophets” (khātamu n-nabiyyīn). However, if you want to pose this as a historical question you need to be aware that in the New Testament (1 Cor. 9,2) Paul writes: ‘If I be not an apostle unto others, yet doubtless I am to you: for the seal of mine apostleship are ye in the Lord.’ The concept “seal of prophesy/apostleship” is a recurring theme in the monotheistic religions. You should also note that there is a lot of discussion both in classical Islamic tafsīr and in Christian exegesis about what “seal of the prophets” actually means.