Atonement For His Sins..

The Noble Prophet (SallAllahu Alayhi wa Sallam) said:

Whatever adversity a Muslim faces due to ailment, worry, sadness, harm or grief, even if he is pricked by a thorn, Allah Almighty makes this (adversity) an atonement (Kaffarah) for his sins.

[Sahih Bukhari, Vol. 4, Page 3, Hadith 5641]