Matthew Henry Commentary Numbers 21:10-20

"And the children of Israel journeyed, and encamped in Oboth. And they journeyed from Oboth, and encamped at Iyeabarim, in the wilderness which is before Moab, toward the sunrising. From thence they journeyed, and encamped in the valley of Zered. From thence they journeyed, and encamped on the other side of the Arnon, which is in the wilderness, that cometh out of the border of the Amorites: for the Arnon is the border of Moab, between Moab and the Amorites. Wherefore it is said in the book of the Wars of Jehovah, Vaheb in Suphah, And the valleys of the Arnon, And the slope of the valleys That inclineth toward the dwelling of Ar, And leaneth upon the border of Moab. And from thence [they journeyed] to Beer: that is the well whereof Jehovah said unto Moses, Gather the people together, and I will give them water. Then sang Israel this song: Spring up, O well; sing ye unto it: The well, which the princes digged, Which the nobles of the people delved, With the sceptre, [and] with their staves. And from the wilderness [they journeyed] to Mattanah; and from Mattanah to Nahaliel; and from Nahaliel to Bamoth; and from Bamoth to the valley that is in the field of Moab, to the top of Pisgah, which looketh down upon the desert." — Numbers 21:10-20 (ASV)

We have here the journeys of the children of Israel, until they came to the plains of Moab, from where they passed over the Jordan into Canaan. The end of their pilgrimage was near. “They set forward.” It would be well if we did this; and the nearer we come to heaven, the more active and abundant we should be in the work of the Lord. The wonderful success God granted to His people is described here, including their actions on the river Arnon, at Vaheb in Suphah, and other places on that river.

In every stage of our lives, indeed, in every step, we should notice what God has done for us; what He did at such a time, and what in such a place, should be distinctly remembered. God blessed His people with a supply of water. When we come to heaven, we shall move to the well of life, the fountain of living waters.

They received it with joy and thankfulness, which made the mercy doubly sweet. With joy must we draw water out of the wells of salvation (Isaiah 12:3). As the brazen serpent was a figure of Christ, who is lifted up for our healing, so is this well a figure of the Spirit, who is poured forth for our comfort, and from whom flow to us rivers of living waters (John 7:38–39). Does this well spring up in our souls? If so, we should take the comfort to ourselves, and give the glory to God.

God promised to give water, but they had to open the ground. God's favors are to be expected when we use the means within our power, but the power itself is only from God.