O my son, if you ever pray, then pray a farewell prayer.  Do not think that you shall return to it ever again.  Know O my son that the believer dies between two good deeds; a good deed that he put forth, and a good deed that he kept back.

—Mu’adh b. Jabal to his son

(Read on pg 27, Aboo Haatim Muhammad Farooq, From the Best of Mankind. Salafi Publications. Birmingham:2006.)