When did Abraham appear and when did Israel become a nation with the Law?

Les explains that after the Tower of Babel, God did something totally different and called out one man, Abram, down at the city of Ur in Babylon. He made the Abrahamic covenant, promising that out of him would come a nation through which God would consummate His whole plan of redemption. Abram came on the scene back at 2,000 B.C. Then 500 years later, Israel is now a nation. They had come out of Egypt under Moses, and they received the Law. That would be 1,500 B.C. From Abraham until Christ's earthly ministry, God dealt almost exclusively with the nation of Israel, with exceptions regarding Gentiles. Once the Law came in, with the tabernacle and temple, that became the makeup of the Old Testament—Israel under the Law with priesthood and temple worship.