How is Abraham’s life divided into segments of five?
Every major segment of Abraham's life is divisible by five. His first call likely came at age 50, he left Haran for the Land of Israel at 75, Isaac was born when he was 100, and he died at 175. Thus his life is divided into segments of five and twenty-five years.
Les explains that Abraham's life is marked by events occurring at ages divisible by five. God stopped Abraham's caravan at Haran, north of Damascus, until his father Terah died, then brought him into the Promised Land. This did not happen in a year or two; years went by, probably as much as twenty-five. Les points out that every segment of Abraham's life is divisible by five: he probably received his first call at 50, left Haran for Israel at 75, saw Isaac born at 100, and died at 175. So his whole life falls into segments of fives and twenty-fives. God told him to leave his father's house and homeland for a land God would show him.