'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.