Long before Jesus’ ancestor, David, came up with Psalm 23, the people of Israel were shepherds - a profession the Egyptians looked down on. It became a well-known metaphor used by the prophets - calling the people of Israel, "God’s flock." I’m not sure why, except for the fact that sheep are notoriously needy and dependent. Put a herd of cattle in a field, and they’ll pretty much take care of themselves. But not sheep. Sheep need ongoing attention – just like us.