Charles Ellicott Commentary Leviticus 26:42

"then will I remember my covenant with Jacob; and also my covenant with Isaac, and also my covenant with Abraham will I remember; and I will remember the land." — Leviticus 26:42 (ASV)

Then will I remember. —This means to perform the covenant God made. The expression “remember” frequently denotes “to be mindful” or “to perform,” especially when used in regard to God; for instance, I have remembered my covenant, etc. (Exodus 6:5–6); He remembered for them his covenant (Psalms 106:45).

My covenant with Jacob, and also my covenant with Isaac, and also my covenant with Abraham. —When they are brought to repentance in this way, the Lord will perform for them the covenant that He made with their ancestors. In this covenant, He not only promised that the Israelites would be a numerous people, but also that they would possess the land forever (Exodus 32:13).

Because the expression “covenant” is exceptionally repeated here before the name of each patriarch, the authorities during the Second Temple period rightly concluded that it refers to three distinct covenants made respectively with each patriarch.

Therefore, the Chaldee Versions render it as: “And I will remember in mercy the covenant that I covenanted with Jacob at Bethel (Genesis 35:9–15), and also the covenant that I covenanted with Isaac at Mount Moriah (Genesis 22:0), and the covenant that I covenanted with Abraham between the divided pieces (of the sacrifices, Genesis 15:18–21).”

The ancients also call attention to the fact that while in all other passages where the three patriarchs are mentioned together, the order is according to their seniority—namely, Abraham, Isaac, and Jacob (Genesis 1:24; Exodus 2:24; Exodus 6:8; Exodus 32:13; Deuteronomy 29:13; Deuteronomy 34:4; 2 Kings 13:23; Psalms 105:8–10; 1 Chronicles 16:16–17)—this is the solitary instance where the regular order is inverted.