John Calvin Reformed @genevareformer

Marking the difference, the Prophet relates, that two or three cities had come to one, to seek drink, and that they were not satisfied, because the waters failed on account of so large a number: for though the fountains could have supplied the inhabitants, yet when such a multitude flowed from every quarter, the very fountains became exhausted.

Matthew Henry Presbyterian @wholebiblehenry

Here, I. God complains of his people's incorrigibleness under the judgments which he had brought upon them in order to their humiliation and reformation. He had by several tokens intimated to them his displeasure, with this design, that they might by repentance make their peace with him; but it had not that effect. 1.

Commenting on Amos 4:6-13

John Gill Reformed Baptist @doctorgill

So two or three cities wandered unto one city, to drink water,.... Two or three cities, that is, the inhabitants of them, being without water, went up and down in quest of any city or place where they could find water for themselves and cattle to drink: but they were not satisfied; could not get enough for their present use and much less to carry...