We divided them (- the people of Moses) into twelve tribes according to the ancestral lineage (to which they belonged). And We sent Our revelation to Moses when his people asked of him (something) to drink (saying), `Strike that rock with your staff.' Then (as he did), there gushed out from it twelve springs, so that all the people now knew their (respective) drinking place. And We outspread the rain clouds to be a shade over them and We sent down for them Manna and quails (saying), `Eat of the pure things wherewith We have provided you.' And they did Us no harm (when they went wrong) but it was to themselves that they had been doing harm.