Will. man leave... ? Note the Figure of speech Erotesis and the Figure of speech Ellipsis (App-6), and render:
"Will [a man] leave the snow [water] of Lebanon for the rock of the field?
Or, shall the cold flowing waters [be forsaken] for strange waters?
snow: i.e. snow [water], used for mixing with wine; or for washing, as in Job 9:30.
which cometh. Omit, and supply the word "leave" in the second clause from the first clause.