David in Shaul's House

סנהדרין קו-קז
§ It is written in one verse: “Doeg the Edomite” (I Samuel 22:9), and it is written in another verse: “And the king said to Doyeig” (I Samuel 22:18). Rabbi Yoḥanan says in explaining the discrepancy: Initially, the Holy One, Blessed be He, sat and was concerned [doeg] that perhaps this person would emerge to undertake an evil path. After he emerged on that path, God said: Alas [vai], that person has emerged to undertake an evil path...
And Rabbi Yitzḥak says: What is the meaning of that which is written: “But to the wicked, God says: What have you to do to declare My statutes, and that you have taken My covenant in your mouth” (Psalms 50:16)? The Holy One, Blessed be He, said to Doeg the wicked: Why do you speak of My statutes and My Torah? When you reach the Torah portion of murderers and the Torah portion of slanderers, how do you teach them? You have violated both. With regard to the end of that verse: “And that you have taken My covenant in your mouth” (Psalms 50:16), Rabbi Ami says: Doeg’s Torah is only insincere lip service, as it is in his mouth but not in his heart. He does not have a profound understanding of the Torah and does not commit himself to the performance of its mitzvot...
Rabbi Yehuda HaNasi says: Doeg and Ahithophel raised four hundred dilemmas with regard to the purity of a cupboard that floats in the air, and they did not resolve even one, an indication of their great knowledge. Rava says: Is it greatness to raise dilemmas? That is not a barometer of greatness, as in the years of Rav Yehuda all of their Torah study was confined to the order of Nezikin, and we study much more than that, and are expert even in tractate Okatzin, the final tractate in the difficult order of Teharot.