Yahweh concludes his message to Edom in verse 15. In verses 16-21, Yahweh speaks through Obadiah to tell the people of Judah that they will possess the land of Edom.
Bible experts are not certain whether verse 15 goes with verse 14 as the end of the previous section, or goes with verse 16 as the beginning of the new section.
This can be stated in active form. Alternate translation: "I will do to you the same things that you did to others" (See: [[rc://en/ta/man/translate/figs-activepassive]])
Here "return on your own head" means they will be punished for those things. Alternate translation: "you will suffer the consequences for the things you have done" (See: [[rc://en/ta/man/translate/figs-idiom]])