And We divided them into twelve tribes , as separate groups ; and when his people asked him for water , We revealed to Moosa , “ Strike the rock with your staff ” ; so twelve springs gushed forth from it ; each group recognised its drinking-place ; and We made the clouds a canopy over them and sent down the Manna and the Salwa ( birds ) on them ; “ Eat of the good things we have provided you ” ; and they did not wrong Us in the least , but they used to wrong themselves .