Charles Spurgeon Commentary Numbers 19:1

"And Jehovah spake unto Moses and unto Aaron, saying," — Numbers 19:1 (ASV)

This ordinance was not given to Moses on Mount Sinai, but in the wilderness of Paran, after the people had broken their covenant with God and were condemned to die. You know Psalm 90—that mournful dirge we read at funerals—which is titled A Prayer of Moses the man of God. He might well write that Psalm, for he lived among a generation of people who were all doomed to die within a short time and to die in the wilderness.

This ordinance was especially appointed to address the circumstances of those who were rendered unclean by the frequent deaths that occurred. A simple and easy way of purification was to be provided for them; and the teaching of this chapter to us is that, since we dwell in a sinful world, there needs to be some simple and ready method of cleansing us, that we may be able to draw near to God.