Midrasz do Przysłów 14:14

From what source did Abraham learn the law? R. Simeon the son of Yohai declared: His two kidneys (kelayot) became like two pitchers filled with water, from which the law flowed forth, as it is said: In the night season my kidneys instruct me (Ps. 16:7). R. Levi maintained: He studied the law by himself, as it is said: The dissembler from his heart shall have his fill from his own ways; and a good man shall be satisfied from himself (Prov. 14:14). He taught the law to his sons, as it is said: For I have known him, to the end that he may command his children (Gen. 18:19).