Allah has guaranteed your livelihood and has commanded you to act. Therefore, the pursuit of that which has been guaranteed to you should not get preference over that whose performance has been enjoined upon you.
But by Allah, most certainly the position is that doubt has overtaken and certainty has been shattered and it seems as if what has been guaranteed to you is obligatory on you and what was made obligatory on you has been taken away from you.
So, hasten towards (good) actions and dread the suddenness of death, because the return of age cannot be hoped for, as the return of livelihood can be hoped for.
Whatever is missed from livelihood today may be hoped tomorrow with increase, but whatever is lost from the age yesterday, its return cannot be expected today.
Hope can be only for that which is to come, while about that which is passed there is only disappointment. So “fear Allah as He ought to be feared and do not die until you are (true) Muslim.” (Qur’an , 3:102)
#NahjulBalagha Sermon 113