Is “Work for your worldly life as if you are living forever, and work for your Hereafter as if you are dying tomorrow.”, a narration of the Prophet, sallallaahu alayhi wa sallam?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

This narration was not said by the Prophet rather it is confirmed that it was a statement of ‘Abdullaah Ibn ‘Amr Ibn Al-‘Aas as reported by Al-Haythami with the wording: "Work for your worldly life as if you are living forever, and work for your Hereafter as if you are dying tomorrow." This narration is also attributed to the Prophet but it is not authentic. Al-Bayhaqi and Ad-Daylami reported that ‘Abdullaah Ibn ‘Amr Ibn Al-‘Aas, narrated that the Prophet said: "Perform the work of a man [in regard to this worldly life] who believes that he will never die, and be careful and fear the Hereafter like a man who fears to die tomorrow.”  However, As-Sayooti classified it as weak. Al-Munaawi said: 'It is weak because the chain of narrators of this narration contains unknown and weak narrators.' 

Allaah Knows best.