إِلَّا مَنِ ٱرْتَضَىٰ مِن رَّسُولٍ فَإِنَّهُۥ يَسْلُكُ مِنۢ بَيْنِ يَدَيْهِ وَمِنْ خَلْفِهِۦ رَصَدًا
Illaa manir tadaa mir rasoolin fa innahoo yasluku mim baini yadihi wa min khalfihee rasadaa
Jedynie posłańcowi, którego Sobie upodobał. I, zaprawdę, On prowadzi przed nim i za nim straż,
except to a messenger he has chosen — and then he sends watchers before him and behind him
This closes a loop the surah opened: the jinn began by reporting that the stations they once used to eavesdrop on heaven are now guarded, and the guard reappears here around the message itself. Rasad names a watch posted to intercept. The exception is narrow, one chosen messenger, and even that channel is escorted at both ends.