Kitāb al-Muʾmin

Hadith 28
trials-afflictionstaqwa
28 - وعن أبي عبد الله (ع) لا يصير على المؤمن أربعون صباحاً إلاّ تعاهده الربُّ تبارك وتعالى بوجَع في جسده أو ذَهاب ماله أو مصيبة يؤجره الله عليها.
28. It has been also narrated that Abu 'Abd Allah (a.s) said: No forty days pass for a believer without the Glorious and most High Lord presenting him with pain in his body or loss of wealth, or an affliction for which Allah rewards him.
Source: Ḥusayn b. Saʿīd al-Ahwāzī