# As you rejoiced over the inheritance of the people of Israel because of its desolation

"As you rejoiced when I made the land of the Israelites desolate"

# I will do the same to you

"I will make your land desolate" or "I will rejoice when your land is desolate" or "I will make other people rejoice because of your desolation."

# Then they will know

"the people of the earth" or "the people of Israel and Judah."