These verses provide an interesting juxtaposition of time frames and references. Verse 21 is a certain reference to Moses, who did lead Israel through the desert, and caused waters to flow our of the rock. The oddity is that verse 20 calls them forth from Babylon rather than the historically accurate Egypt. In this case Isaiah/the Lord is mixing historical time frames to the point of showing the mercy of the Lord. He will lead them now, he has lead them in the past.
The sad lament of verse 22 is the recognition that for all of the assistance of the Lord through his prophets, including the miraculous preservation in the wilderness, there is now no peace. Linking this lament to verse 18's clear indication of the events as the fault of the children of Israel places this verse in the proper context. All might have been different. The possibility was there, the Lord was there, and the Lord performed miracles for them. Yet there is no peace because they have chosen to not follow the counsel.
For the Lehites as well as the Israelites, the admonishion is clear. Their sufferings have been brought on by their unbelief, in the face of miracles and prophets speaking clearly.