The miry places thereof and the marshes thereof גְבָיָאו, "its pools and sloughs" (comp. Isaiah 30:14, where the term-signifies a reservoir for water, or cistern), were the low tracts of land upon the borders of the Dead Sea, which in the rainy season, when its waters overflowed, became covered with pools (see Robinson, 'Bibl.
Res.,' 2.225). These, according to the prophet, should not be healed, obviously because the waters of the temple-river should not reach them, but should be given to salt. When the waters of the above-mentioned pools have been dried up or evaporated, they leave behind them a deposit of salt (see Robinson, 'Bibl.
Res.,' 2.226), and Canon Driver, following Smend, conceives that the above-named miry places and marshes in the vicinity of the Dead Sea were to be allowed to remain as they were on account of the excellent salt which they furnished.
(On the supposed (!) excellence of the salt derived from the Dead Sea, Thomson's 'Land and the Book,' p. 616, may be consulted.) If this, however, were the correct import of the prophet's words, then the clause would describe an additional blessing to be enjoyed by the land, viz.
that the temple-river would not be permitted to spoil its "salt-pans;" but the manifest intention of the prophet was to indicate a limitation to the life-giving influence of the river, and to signify that places and persons unvisited by its healing stream would be abandoned to incurable destruction.
"To give to salt" is in Scripture never expressive of blessing, but always of judgment (see Deuteronomy 29:23; 9:47; Psalms 107:34; Jeremiah 17:6; Zephaniah 2:9).