New Defender's Study Bible Notes
18:19 command his children. This is the first specific reference in the Bible to the teaching of children, indicating that such instruction is the primary responsibility of the father and should take the form of commandments, centering first on the ways of the Lord, then on justice and judgment to fellow-men.
18:20 very grievous. The iniquity of the Amorites was not yet full (Genesis 15:16), but these cities of the plain had reached God’s limit, especially in view of their reversion to gross wickedness after the marvelous deliverance God gave them through Abraham and after seeing and hearing the testimony of Melchizedek, and even the witness of Lot.