تزكية النفوس
Suhayb ibn Sinān Ar-Rūmi (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "How wonderful the affair of the believer is! Indeed, all of his affairs are good for him. This is for no one but the believer. If something good happens to him, he is grateful to Allah, which is good for him. And if something bad happens to him, he has patience, which is good for him."
عن صُهيب بن سِنان الرومي -رضي الله عنه- مرفوعاً: «عجَبًا لِأَمر المُؤمِن إِنَّ أمرَه كُلَّه له خير، وليس ذلك لِأَحَد إِلَّا لِلمُؤمِن: إِنْ أَصَابَته سَرَّاء شكر فكان خيرا له، وإِنْ أَصَابته ضّرَّاء صَبَر فَكَان خيرا له».
شرح الحديث :
The Messenger of Allah (may Allah's peace and blessings be upon him) admired the affairs of the believer, as goodness and success are always on his side, which is unique. Then, the Prophet (may Allah's peace and blessings be upon him) said that the believer is on a worthy mission, regardless of what happens to him. If a misfortune befalls him, he is patient, waits for help from Allah, and seeks divine reward. Also, if he is endowed with a blessing, be it religious, such as knowledge or good deeds, or mundane such as wealth or family, he thanks Allah and obeys Him. In both cases, the good and the bad state of affairs of the believer are nothing but good for him.