Chapter 19: Sprinkling Water = Clean Sin!
Directions are given on how to sacrifice a red heifer (red cow). In the ceremony, water is used as a purification of sin. Ceremonially people who are unclean are “sprinkled” with water to be clean.
I am guessing that this ceremony might have some aspects wrapped up into baptism, and quite possibly where the Catholics started sprinkling water in baptism, instead of by immersion.
Chapter 20: Water from a Rock
The congregation of Israel is wandering through the Desert of Zin, when they run out of water and start to murmur against Moses and Aaron. While there in Kadesh Miriam dies.
Moses and Aaron go to the tabernacle and pray to God. God tells Moses to gather the congregation and then smite a rock and they will have water. So Moses smacks a rock two time and water comes flowing out of it. (See Verses: 8-11).
Moses asks the king of Edom for permission to pass through his land and he refuses to give them permission. Aaron dies and Eleazar becomes the new high priest.