فَلَمَّا وَرَدْنَ الْمَاءَ زُرْقًا جِمَامُهُ وَضَعْنَ عِصِيَّ الْحَاضِرِ الْمُتَخَيِّمِ
When they reached water whose gathered pools looked clear blue, they settled there as a camper puts down the staff of residence.
Waradna al-māʾ means they arrived at a water source. Zurqan jimāmuhu describes the clear blue appearance of the gathered pools or reserves. Then waḍaʿna ʿiṣiyya al-ḥāḍir al-mutakhayyim uses putting down the resident camper’s staff to signify settling temporarily.
Stopping at water was a practical part of desert travel. The idiom gives that routine action a vivid material image.