Leviticus 18:3 Commentary - Ellicott's Commentary for English Readers (Old and New Testaments)

(3) After the doings of the land of Egypt.—During their sojourn in Egypt the Israelites became familiar with the practices which obtained in the land of their bondage, and as they adopted some of them (see Lev. 17:7), they are here solemnly warned to eschew those which are especially proscribed in the sequel.

And after the doings of the land of Canaan. The danger of imitating the customs which they had for centuries witnessed in the land they quitted, was greatly increased by the fact that these licentious practices obtained in worse forms in the land which they were to inherit. It is therefore against the past and the future that they are here warned.

Neither shall ye walk in their ordinances. As some of “the doings” referred to may have been simple custom, not based upon the law of the country where they obtained, the Lawgiver here emphatically condemns the acts which were legalised, declaring them to have no authority whatever. (See Lev. 18:30.)