Musnad Ahmad 5:88

Marwan ibn Mu'awiyah al-Fazari narrated to us, al-Azhar ibn Rashid al-Kahili informed us, from al-Khidr ibn al-Qawwas, from Abu Sakhilah, who said: Ali said: "Shall I not inform you of the best verse in the Book of Allah, the Exalted, which the Messenger of Allah, may Allah bless him and grant him peace, narrated to us? '{Whatever of misfortune befalls you, it is because of what your hands have earned, and He pardons much} [Ash-Shura: 30].' And I will explain it to you, O Ali: Whatever befalls you of illness, or punishment, or trial in the world, it is because of what your hands have earned. And Allah, the Exalted, is too Generous to repeat the punishment upon them in the Hereafter. And whatever Allah, the Exalted, has pardoned in the world, Allah, the Exalted, is too Forbearing to return to it after His pardon."