THE “FIRSTBORN” IS REFERRING MORE TO AN OFFICIAL “OFFICE” THAN THE ORDER OF BIRTH.
Then YAHUSHA said to Moses, “Now count all the firstborn sons in Yisharal who are one month or older, and make a list of their names. The Levites must be reserved for Me as SUBSTITUTES FOR THE FIRSTBORN SONS OF YISHARAL for I am Yahuah. And the Levites’ livestock must be reserved for Me also as SUBSTITUTES FOR THE FIRSTBORN LIVESTOCK OF THE WHOLE NATION OF YISHARAL.”
So Moses registered the firstborn sons of the people of Yisharal, just as YAHUSHA had instructed and there were 22,273 (one month old+).
Then YAHUSHA said to Moses, “There are 273 more firstborn sons of Yisharal than there are Levites so to redeem these extra firstborn sons, collect five pieces of silver (57g) for each of them and give the silver to Aaron and his sons as the redemption price for the extra firstborn sons.”
So Moses collected 1,365 pieces of silver (15.5kg) on behalf of these firstborn sons of Yisharal and gave the redeeming silver to Aaron and his sons, just as YAHUSHA had instructed.