Maimonides, Letter to Obadiah the Proselyte
From Maimonides’ letter:
…Abraham our Father taught the people, opened their minds, and revealed to them the true faith and the unity of God; he rejected the idols and abolished their adoration; he brought many children under the wings of the Divine Presence; he gave them counsel and advice, and ordered his sons and the members of his household after him to keep the ways of the Lord forever, as it is written, “For I have known him to the end that he may command his children and his household after him, that they may keep the way of the Lord, to do righteousness and justice” (Gen. 18:19).