The beginning of strife is as when one letteth out water - As soon as the smallest breach is made in the dike or dam, the water begins to press from all parts towards the breach; the resistance becomes too great to be successfully opposed, so that dikes and all are speedily swept away. Such is the beginning of contentions, quarrels, lawsuits, etc.
Leave off contention, before it be meddled with - As you see what an altercation must lead to, therefore do not begin it. Before it be mingled together, התגלע hithgalla, before the spirits of the contending parties come into conflict - are joined together in battle, and begin to deal out mutual reflections and reproaches. When you see that the dispute is likely to take this turn, leave it off immediately.
The figure is taken from the great tank or reservoir upon which Eastern cities often depended for their supply of water. The beginning of strife is compared to the first crack in the mound of such a reservoir. At first a few drops ooze out, but after a time the whole mass of waters pour themselves forth with fury, and it is hard to set limits to the destruction which they cause.
Before it be meddled with - literally, “before it rolls, or rushes forward.”