﴿ وَنَبِّئْهُمْ أَنَّ ٱلْمَآءَ قِسْمَةٌۢ بَيْنَهُمْ ۖ كُلُّ شِرْبٍۢ مُّحْتَضَرٌۭ ﴾

“And let them know that the water [of their wells] is to be divided between them, with each share of water equitably apportioned.””

(And inform them that the water) of the well (is to be shared between (her and) them) one day for her and one day for them. (Every drinking will be witnessed) Salih informed them of this. They agreed to comply and observed this for a while but then their wretchedness overtook them.