Everyonethatlappethofthewater - asadog - The original word ילק yalok is precisely the sound which a dog makes when he is drinking.
Matthew Henry
Concise Bible Commentary
God provides that the praise of victory may be wholly to himself, by appointing only three hundred men to be employed. Activity and prudence go with dependence upon God for help in our lawful undertakings. When the Lord sees that men would overlook him, and through unbelief, would shrink from perilous services, or that through pride they would vaunt themselves against him, he will set them aside, and do his work by other instruments. Pretences will be found by many, for deserting the cause and escaping the cross. But though a religious society may thus be made fewer in numbers, yet it will gain as to purity, and may expect an increased blessing from the Lord. God chooses to employ such as are not only well affected, but zealously affected in a good thing. They grudged not at the liberty of the others who were dismissed. In doing the duties required by God, we must not regard the forwardness or backwardness of others, nor what they do, but what God looks for at our hands. He is a rare person who can endure that others should excel him in gifts or blessings, or in liberty; so that we may say, it is by the special grace of God that we regard what God says to us, and not look to men what they do.