Charles H. Spurgeon on Psalms 126:4

As the streams in the south. Then shall our captivity be perfectly changed, even as the rivers or waters in the south, which by the mighty work of God were dried up and utterly consumed. Whether ye understand here the Red Sea, or else the river of Jordan, it matters little. The similitude is this: Like as by the mighty hand thou broughtest to pass miraculously that the waters were dried up and consumed, so dry up, O Lord, and bring to nothing all our captivity. Some do interpret this verse otherwise; that is, Turn our captivity, O Lord, as the rivers in the south, which in the summer are dried up in the desert places by the heat of the sun, but in the winter are filled up again with plenty of water. —Martin Luther.