Kabbalah zu Schemuel II 12:11

With all this, we find that David accepted upon himself afflictions and fasts, as it says “My knees were week due to fasting” (Psalms 109:24), and that which he was troubled from his kingdom was because his sin was that he had Uriah killed with the sword of Ammon, as it says in the Zohar in Beresheet. But the punishment for what he sinned with Uriah was written and he accepted, meaning what Nathan the Prophet said to him “I will raise up evil against you out of your own house” (Shmuel B 12:11). One who damages his Brit must surely suffer afflictions and fasts all his life as David did.