'Appear Before Me' in the Bible

You shall observe the feast of unleavened bread. Seven days you shall eat unleavened bread, as I commanded you, at the time appointed in the month Abib (for in it you came out from Egypt), and no one shall appear before me empty.

The firstborn of a donkey you shall redeem with a lamb: and if you will not redeem it, then you shall break its neck. All the firstborn of your sons you shall redeem. No one shall appear before me empty.

When you come to appear before me, who has required this at your hand, to trample my courts?