Thou didst cleave the fountain and the flood: thou driedst up mighty rivers.
Thou didst cleave the fountain and the flood - Thou didst cause the water of the fountain to break forth by cleaving-referring to Exodus 17:5-6; Numbers 20:11; Job 28:10.
Thou driedst up mighty rivers - as the Jordan (Joshua 3:13). Not easily dried up: never so by the sun. The Chaldaic adds to the Jordan Arnon and Jabbok. Numbers 21:14 implies that some miracle was performed at Arnon similar to that at the Jordan (cf. Deuteronomy 2:36-37). The "book of the wars of the Lord" may have had some such tradition from which the Chaldeans derived it.