Chp. 17 verse 9 - Chp. 18 verse 15: Hashem brings a plague on the people and Aaron stops it with his fire pan of incense. Continues with the test of the staffs to prove that the tribe of Levi was chosen by Hashem. Chp, 18, begins with warnings to the people about the Mishkan. Hashem defines the position of the Levites. Continues with the 24 gifts given to the priests.