“Aware of the Offspring”

Genesis 49: 28: “All these are the twelve tribes of Israel, and this is what their father said to them when he blessed them. He blessed them, every one with the blessing appropriate to him.” Although Jacob could seem pretty oblivious concerning his children when they were younger, it is uncanny how accurate he was in giving the “appropriate blessing” to each of them at the end of his life. How do we know our children—from actual flesh and blood interaction, or from inane online games based on astrology and other speculation?