Isaac was the miracle baby, born to parents aged 100 and 90. He grew up knowing he was the impossible child, the source of his parents' laughter and joy. He was the sole heir to a massive promise.
He grew up in the shadow of his half-brother Ishmael's mockery and subsequent exile. He learned early that being "chosen" involves separation and loss.
He was formed by the intense love of his father Abraham. He is the first person in the Bible explicitly described as being "loved" by his father (Gen 22:2).