God told Moshe and Aharon to teach the nation the laws of the Red Heifer (Parah Adumah). The unblemished animal, which has never had a yoke upon it, was to be given to Elazar, Aharon’s son, who must slaughter it outside the camp. It was then to be burned by a different Kohen, who must also throw some cedar wood, hyssop and crimson thread into the fire. Both he and Elazar would become ritually impure (tameh) through this preparatory process. In contrast, the ashes of the Heifer, when mixed with water, were used to purify someone who has become tameh through coming into contact with a corpse.
After the ashes are mixed with water, a ritually pure person (tahor) sprinkled the mixture on the tameh person, using a bundle of hyssop. By doing so, the one who sprinkled becomes tameh. The Israelites came to the wilderness of Tsin, where Miriam, Moshe and Aharon’s sister, died. The people complained that they had no water and would have been better off staying in Egypt.
God told Moshe to take his staff and speak to a rock in front of the nation, after which water will emerge from the rock. However, Moshe struck the rock twice (instead of speaking to it). Although the rock produced abundant water, God told Moshe and Aharon that they would not enter the Land.
Moshe sent messengers to the king of Edom, asking him to allow the Israelites to travel from Kadesh through his land. Despite Moshe’s assurances that they would not take any of his resources, Edom refused and threatened the Israelites militarily. The Israelites turned away.
The nation travelled from Kadesh to Mount Hor. Upon God’s command, Moshe, Aharon and Elazar ascended Mount Hor. Elazar donned Aharon’s special Kohen Gadol (High Priest) garments, after which Aharon died. The nation mourned Aharon’s death for 30 days. Israel was attacked by the Cana’anites and defeated them.
After the nation travelled on, the people again became thirsty for water. After complaining, many people were killed by a plague of serpents. Moshe prayed for those who have been bitten but had not yet died. God told him to fashion a copper snake, which miraculously healed anyone who looked at it.
The nation came to the border of Moab, where they found a well. They composed a song about the well.
After denying the Israelites the right to pass through his land, the king of Sichon waged war against them. The Israelites defeated him, before defeating Og, the mighty king of Bashan, who also attacked them.