"You are the best nation produced for mankind, enjoining the good"; meaning: by affirming the oneness of Allah (Tawhid), "and forbidding the evil"; meaning: from associating partners with Allah (Shirk).
Muhammad said: Regarding His saying: "You are"; it is said: its meaning is: you are.
Yahya: on the authority of Abu al-Ashhab, on the authority of al-Hasan, who said: The Messenger of Allah (peace be upon him) said: "You fulfill