It can be written clearly what the word "this" refers to. Alternate translation: "Why are you untying and taking the colt" (See: [[rc://en/ta/man/translate/figs-explicit]])
Jesus will send it back promptly when he is finished using it. Alternate translation: "will immediately send it back when he no longer needs it" (See: [[rc://en/ta/man/translate/figs-explicit]])