Takest the sum. Or, “take the census” (RSV). The population had been estimated at the time of the Exodus as “about six hundred thousand on foot that were men, beside children” (see on ch. 12:37). Now, a more accurate census was to be taken.
A ransom. Literally, “a covering,” in the same sense that insurance “covers” a man and releases him from further obligation. The people were obligated to God; they might discharge that obligation by paying the “ransom.” Their lives were considered forfeited to God until God’s claim upon them was met. In settling the claim they acknowledged God’s goodness and mercy.
For his soul. Rather, “for himself’ (RSV), that is, for his “whole spirit and soul and body” (1 Thess. 5:23). This is obviously the meaning, for the statement is concerned with a living man, not with some immaterial part of his being or with a disembodied spirit.
No plague. That is, no punishment because of carelessness or disobedience.