Sayyiduna Umar (may Allah be pleased with him) would not include any verse in the Qur'an until two men testified to it. Then an Ansari man came to him and informed him about the last two verses of Surah At-Tawbah: "There has certainly come to you..." (i.e., the Messenger of Allah has come to you). So Sayyiduna Umar (may Allah be pleased with him) said: I do not seek any other testimony from you regarding this; this matter is also established from the Messenger of Allah (peace and blessings be upon him). Thus, he included these verses in the Mushaf.
Hadith Referenceسنن سعید بن منصور / كتاب التفسير / 1053
Hadith Gradingمحدثین:سنده ضعيف للانقطاع بين يحيى بن جعدة وعمر