There were 273 more firstborn sons in Israel from the non-Levite tribes than there were Levite males (compare Leviticus 3:39). The Levites acted as substitutes for Israel's firstborn sons (3:41; see study note on 3:11–13). The law required a redemption price of five pieces of silver for each extra firstborn son (Numbers 3:46–48; compare Leviticus 27:6).
It is unclear who paid this cost. This arrangement for special substitutes points to Christ’s role as a substitute. Through his death, Christ paid the redemption price for all humanity (see Mark 10:45; Galatians 3:13; Ephesians 1:7; Hebrews 9:15).