Place it right after the English line in your edit, as the response beat before cutting back to the main speaker. Follow it with a brief reaction sound if the scene needs a second punch, or precede it with the original phrase so the call-out reads clearly in sequence.
About this sound
This short clip is a man delivering the Arabic line 'dah inglizi dah ya Morsy' in just under two seconds, spoken fast with clear disbelief. It feels funny and baffled, like catching someone suddenly switching languages mid-sentence and calling it out on the spot for everyone listening.