Kabbalah for Shabbat 111:17

The benefit of one who protects his Brit is explained in the punishment, since he (King David) says that since he did not protect the sign of the covenant accordingly he would have been sent to Dumah had the Creator not been his defense attorney, as it says in the Prologue of the Zohar, verse 137. David was afraid of Dumah even when he did something that was permitted, since everyone who goes to war for the House of David writes his wife a divorce document. The fact that he did not properly guard the sign of the covenant (brit) properly, his Torah was not enough to protect him from the suffering, and our Sages say that King David was the head of the Sanhedrin and the law is according to him in all places, as it says about him “a man of understanding, and God is with him” (Shmuel A 16:18) meaning that the Halacha is according to him, so who would have been a defense attorney for him without knowing all the laws? Surely he would have been sent to Dumah.