Musnad Abu Ya'la al-Mawsili 2:21

Mus'ab ibn 'Abd Allah narrated to us, 'Abd al-'Aziz ibn Muhammad narrated to us, from Muhammad ibn Abi Humayd, from Zayd ibn Aslam, from his father, from 'Umar ibn al-Khattab, who said: I was sitting with the Messenger of Allah (may Allah bless him and grant him peace), and he said: "Inform me as to who are the people of faith with the best faith." They said: "O Messenger of Allah, the angels." He said: "They are as such, and it is rightfully theirs, and what would prevent them when Allah has placed them in the position He has placed them? But [it is] others." They said: "O Messenger of Allah, the prophets whom Allah honored with His message and prophethood." He said: "They are as such, and it is rightfully theirs, and what would prevent them when Allah has placed them in the position He has placed them? But [it is] others." They said: "O Messenger of Allah, the martyrs who were martyred alongside the prophets." He said: "They are as such, and it is rightfully theirs, and what would prevent them when Allah has honored them with martyrdom alongside the prophets? But [it is] others." They said: "Then who, O Messenger of Allah?" He said: "Peoples in the loins of men who will come after me. They will believe in me without having seen me, and they will attest to me without having seen me. They will find the suspended parchment and act upon what is in it. These are the people of faith with the best faith."