Numbers 3:43

This result, when compared with the number of male adults (603,550, compare Numbers 2:32), is small, the usual proportion of first-born sons to a total male population being about one in four: and the explanation offered is that the law of Exodus 13:1, prescribed a dedication of those only who should be firstborn “thenceforward”.

On the other hand, the number is very large to be born among two millions of persons in a single year; and it must be admitted, that some unusual causes must have been concerned. Such, not to mention the divine blessing, may be found in the sudden development of national energies which would immediately ensue on the Exodus. Before that event, the miserable estate of the people, and especially the inhuman order for the destruction of their first-born, would check very seriously the ratio of marriages and births; and this ratio would naturally, when the check was removed, exhibit a sudden and striking increase.