No fatigue, nor disease, nor sorrow, nor sadness, nor hurt, nor distress befalls a Muslim, even if it were the prick he receives from a thorn, but that Allah expiates some of his sins for that.

Abu Said & Abu Hurairah - Sahih Bukhari & Muslim

Amazing is the affair of the believer, verily all of his affairs are good and this is not for no one except the believer. If something of good/happiness befalls him he is grateful and that is good for him. If something of harm befalls him he is patient and that is good for him.

Suhaib - Sahih Muslim

Indeed, Allah said: When I afflict My servant regarding his two beloved things (his eyes) and he shows patience, I compensate him with Paradise.

Anas ibn Malik - Sahih Bukhari