Uqba bin Amir reported,

I heard the Messenger of Allah ﷺ say, "There are two men of my community. One of them rises during the night and struggles with himself to reach purification, while knots are upon him, so he performs wudu. When he washes his hands, a knot is untied. When he wipes his head, a knot is untied. When he washes his face, a knot is untied. When he wipes his head, a knot is untied. When he washes his feet, a knot is untied. Then the Lord says to those behind the veil, 'Look at this servant of Mine, struggling with himself. Whatever this servant of Mine asks of Me is his.'"

وسمعت رسول الله ﷺ يقول رجلان من أمتي يقوم أحدهما من الليل فيعالج نفسه إلى الطهور وعليه عقد فيتوضأ فإذا وضأ يديه انحلت عقدة وإذا مسح رأسه انحلت عقدة وإذا وضأ وجهه انحلت عقدة وإذا مسح رأسه انحلت عقدة وإذا وضأ رجليه انحلت عقدة فيقول الرب عز وجل للذين وراء الحجاب انظروا إلى عبدي هذا يعالج نفسه ما سألني عبدي هذا فهو له