From the firstborn of the people of Israel he took the money, 1,365 shekels, by the shekel of the sanctuary.
Here is the exchange made of the Levites for the first-born. 1. The first-born were numbered from a month old, Num 3:42, Num 3:43. Those certainly were not reckoned who, though first-born, had become heads of families themselves, but those only that were under age; and the learned bishop Patrick is decidedly of opinion that none were numbered but those only that were born since...
Commenting on Numbers 3:40-51
And Moses gave the money of them that were redeemed,.... That were redeemed this way, and not by Levites, as in Num 3:49, but by money, paying five shekels a head: unto Aaron and his sons; to whom the Levites were given; and this money, as a recompence for the deficiency of the number of them, to answer to the firstborn exchanged for them: according...
Of the firstborn of the children of Israel took he the money; a thousand three hundred and threescore and five [shekels], after the shekel of the sanctuary: (q) Or the two hundred seventy and three which were more than the Levites.