Jami` at-Tirmidhi Book 48, Hadith 179
“Whomsoever of you the door of supplication is opened for, the doors of mercy have been opened for him. And Allah is not asked for anything - meaning - more beloved to Him, than being asked for Al-`Āfiyah.” And the Messenger of Allah (ﷺ) said: “The supplication benefits against that which strikes and that which does not strike, so hold fast, O worshippers of Allah, to supplication.”
“O Allah, cool my heart with snow and hail and cold water. O Allah, cleanse my heart of sins as You cleanse a white garment of filth (Allāhumma barrid qalbī bith-thalji wal-baradi wal-mā’il-bārid. Allāhumma naqqi qalbī min al-khaṭāyā kamā naqqaitath-thawbal-abyaḍa min ad-dannas).”
“Ishaq bin Mansur narrated to us, from Isra’il” with this (Another chain) Bilal narrated that the Messenger of Allah (ﷺ) said: “Hold fast to Qiyam al-Lail, for it is the practice of the righteous before you, and indeed Qiyam al-Lail is a means of nearness to Allah, a means of prevention from sin, an expiation for bad deeds, and a barrier for the body against disease.”