Saying 'Allah and His Messenger know best'

Q: What is the ruling on saying: "Allah and His Messenger know best"?

A: Since the Messenger (peace be upon him) has already died, it is only permissible to say: "Allah knows best". This is because the phrase which is mentioned in the question means that the Messenger (peace be upon him) knows things that happened after he (peace be upon him) had passed away and things that will happen in future though Allah has not informed His Messenger of such things through Wahy (Revelation). Having the knowledge of the future is something which is specific only to Allah Alone (Glorified and Exalted be He). On the other hand, saying the phrase which is mentioned in the question was permissible during the lifetime of the Messenger as he was being taught by Allah through Wahy.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.