Numbers 3:44-45 (NLT) 44 Then the LORD said to Moses, 45 “Take the Levites as substitutes for the firstborn sons of the people of Israel. And take the livestock of the Levites as substitutes for the firstborn livestock of the people of Israel. The Levites belong to me; I am the LORD.
The word “substitute” suggests something less than the best. Sometimes it is simply necessary for substitution to be made because “the best” becomes less than sufficient. Consider the “1st team” basketball player who out of exhaustion is much less productive than his substitute. It was appropriate for the Levites to serve as substitutes for the firstborn sons of Israel because they had been dedicated to the priesthood. Jesus, our high priest, was dedicated to serving as our substitute, suffering death for our sin, ransoming and thereby entitling us to the gift of God which is eternal life. (cf. Mk. 10:45; Rom. 6:23) He gave his best that we might in turn give ours! (Rom. 12:1)