This implies that they do not need to be afraid of the consequences for killing Amnon. This can be stated clearly. Alternate translation: "Do not be afraid that you will be blamed for killing the king's son" (See: [[rc://en/ta/man/jit/figs-explicit]])
Absalom asks this rhetorical question to emphasize that he will be blamed for killing Amnon because he is commanding them. This can be written as a statement. Alternate translation: "I have commanded you to do this." or "I will be the one guilty for killing him because I have commanded you to do this." (See: [[rc://en/ta/man/jit/figs-rquestion]] and [[rc://en/ta/man/jit/figs-explicit]])
What Absalom has commanded them to do may be stated in the question. Alternate translation: "not commanded you to kill him" (See: [[rc://en/ta/man/jit/figs-ellipsis]])