Matthew Poole and continuators on Numbers 31:30

30 And of the children of Israels half, thou shalt take one portion of fifty , of the persons, of the beeves, of the asses, and of the sheep, of all manner of beasts, and give them unto the Levites, which keep the charge of the tabernacle of the LORD.

Whereas the former part was one of 500, the reason of the difference is partly because this was taken out of the peoples portion, whose hazards being less than the others, their gains also in all reason were to be less; partly because this was to be distributed into more hands, the Levites being now numerous, when the Priests were but few.

Marginal references: Or, goats.; chap. 3. 7, 8, 25, 31, 36.