What did the Old Testament covenants promise about God turning to the Gentiles?

Les explains that this was part and parcel of the Old Testament covenants: the day would come when Israel had completed the promises, and then God would turn to the Gentile world. In Isaiah 49:6, God says it is a light thing for the servant to raise up the tribes of Jacob and restore the preserved of Israel; He will also give him as a light to the Gentiles and salvation to the end of the earth. Jacob was the nation as a whole, while Israel was the believing remnant. Israel was to have had the opportunity, and to a certain extent did, since every word of this book was written by Jews, but God had even more for the nation. They rejected it in unbelief, yet God's idea was to go to the Gentile world through this covenant people. God from the beginning knew the day would come when He would go to the whole Gentile world with His salvation. When Israel constantly rejected it, He sent the nation into dispersion, took away their temple, and took away their land.