Glitchfusion
According to Genesis 17, Abram was 99 years old when God promised him a son (Isaac) through Sarai. Genesis 17:17 also states that Abram said to himself, "Can a child be born to a man who is a hundred years old? Can Sarah, who is ninety years old, bear a child?". This implies that Sarai was 90 years old at the time of God's promise.