Albert Barnes Commentary 2 Kings 3:20

"And it came to pass in the morning, about the time of offering the oblation, that, behold, there came water by the way of Edom, and the country was filled with water." — 2 Kings 3:20 (ASV)

When the meat offering was offered—that is, about sunrise, when the morning sacrifice was offered. Compare 1 Kings 18:29.

There came water by the way of Edom—The Wady-el-Ahsy drains a considerable portion of northern Edom. Heavy rain had fallen during the night in some part of this tract, and with the morning a rush of water came down the valley, filling the pits.