﴿ قَالَ ذَٰلِكَ مَا كُنَّا نَبْغِ ۚ فَٱرْتَدَّا عَلَىٰٓ ءَاثَارِهِمَا قَصَصًۭا ﴾

“[Moses] exclaimed: "That [was the place] which we were seeking!, And the two turned back, retracing their footsetps,”

(He said) Moses said: (This is that which we have been seeking) as an indication from Allah to Khidr (they retraced their steps again) they went back, following their own footsteps.