1 Chronicles 27:23

But David took not the number of them from twenty years old and under: because the LORD had said he would increase Israel like to the stars of the heavens.

But David took not the number ... from twenty years old and under. The meaning is, that the census which David ordered did not extend to all the Israelites; because to contemplate such an enumeration would have been to attempt an impossibility (Genesis 28:14); and, besides, would have been a daring offence to God. The limitation to a certain age was what had probably quieted David's conscience as to the lawfulness of the measure, while its expediency was strongly pressed upon his mind by the army arrangements he had in view.