It comes from earlier than that. God wanted "first fruits" of things in Deuteronomy and Leviticus (earlier if you include some events in Exodus), where God was telling the Israelites how to obey God and be a righteous people, after He led them out of Egypt. But, God doesn't need any of our sacrifices, money, or things. The sacrifices were forward pointing to Jesus, and to feed the Levite priests who weren't portioned any land (to grow crops or cattle, leaving them at the mercy of the other tribes for food) in the newly conquered land of Israel, and the first fruits were meant to help other people (i.e. the church), as most Christians understand it today, which is what tithing is. Through the parable of the talents that Jesus taught, it's understood that God blesses us (with wealth, things, or even personal talent) so we can also help others, and not just use it to enrich ourselves.