Does that sound like a New Covenant? Think about that.
Did you hear that? "I will establish My covenant between Me and you and your seed after you in their generations." They were already included within the covenant God made with Abraham! Even though they did not exist yet, they were included in that covenant.
This almost sounds like the New Covenant. It involves eternity.
"And I will be a God unto you, and you shall know Me."—Hebrews 8.
Here is the starting point and the foundation that Paul is referring to in the book of Galatians. Consider what happened to Israel in Egypt, because that is what precipitated the making of the Old Covenant. They learned the way of the heathen so well that it was almost permanently ingrained in their national character and therefore their conduct. They had apparently completely lost the Sabbath, and God had to reveal it to them (in Exodus 16) before they even got to Mt. Sinai.
