CANALS (Heb. יְאֹר, H3284, pl. יְאֹרִ֖ים, is a word borrowed from Egyp. where it means “the Nile”). Translated “streams” in Exodus 7:19; 8:5 KJV, ASV; “brooks” in Isaiah 19:6 KJV; “streams” in ASV. In all the foregoing, ASVmg. and RSV text have “canals.” Nahum 3:8 KJV, ASV, and RSV have “sea,” while ASVmg. has “canals.” In all the above VSS, irrigation canals branching off from the Nile appear to be meant. This is the significance of the pl.
International Standard Bible Encyclopedia (1915)
The word "canals" occurs in several places in the Revised Version, margin (Ex 7:19; 8:5; Isa 19:6; Na 3:8). ye’or is an Egyptian word, the designation of the Nile (Brugsch, Geogr, I, 8, 78). The proper name of the Nile as a god was Hapi. There were several common designations of the Nile, but the usual one was ye’or, Hebrew plural ye’orim. The primary meaning of ye’or in Egyptian is not certain, but its significance in use for the Nile is plain enough. All the waters in Egypt were of the Nile and this word ye’or was used to denote all of them, the Nile and all its ramifications through the whole irrigating system. Thus ye’orim, Niles, came to be used. As only the main channels of the Nile had much current, the ye’orim came naturally to convey the idea of sluggishness. In the account of the plagues (Ex 7:19), names are used descriptively to designate the different waters of Egypt: neharoth, "flowing streams," for the main channels of the river, and ye’orim for other streams, which by contrast must mean, as it should according to its use by the Egyptians, "the sluggish streams," i.e. "canals," as it is rendered by the Revisers. This meaning of the word being thus clearly established, it is appropriately used in the Revised Version, margin in the other instances of its occurrence in like circumstances.
M. G. Kyle