SAND (חוֹל, H2567, sand; ἄμμος, G302, sand). Although references to sand are numerous, on only one occasion in the Bible narrative does the actual sand of the Middle E figure in the record—when Moses buried an Egyp. whom he had killed, in the hope of keeping the affair secret (Exod 2:12). All other references are fig., the most common being to speak of sand grains as an indication of large numbers or amounts.
The regions in which the Bible narrative unfolds contain many areas of sand and sand-hills. From Egypt, through the wilderness of Sinai, the Israelites would have been marching over sand for a good part of their journey. Although the desert of Sinai is rocky rather than sandy, patches of loose sand are encountered very frequently. Within the Promised Land, there was and is a wide belt of coastal sand dunes bordering the Mediterranean along the shores of southern Pal.; this has tended to spread inland unless stopped by forest planting or marram grass. It is the true “sand of the sea shore.”
Apart from this coastal sand, it should also be borne in mind that, in a dry climate, every river and torrent eroding the barren surface of the land quickly becomes charged with a load of sand and debris, which it spreads along its banks where it debouches into the plain. This gives point to the Lord’s parable of the house built on the sand (Matt 7:26); presumably it was built on these valley deposits, beside the river, where it was within reach of the flood level of the storm water.
References to sand as symbolizing very large numbers occur from Genesis 22:17 onward; not only Abraham’s descendants are so described, but also the corn gathered by Joseph in Egypt (Gen 41:49) and, rather curiously, the wisdom of Solomon and his largeness of mind (1 Kings 4:29). In Matthew 7:26, of course, sand also serves as a symbol of instability or lack of foundation.
International Standard Bible Encyclopedia (1915)
Sand is principally produced by the grinding action of waves. This is accompanied by chemical solution, with the result that the more soluble constituents of the rock diminish in amount or disappear and the sands tend to become more or less purely silicious, silica or quartz being a common constituent of rocks and very Insoluble. The rocks of Palestine are so largely composed of limestone that the shore and dune sands are unusually calcareous, containing from 10 to 20 per cent of calcium carbonate. This is subject to solution and redeposition as a cement between the sand grains, binding them together to form the porous sandstone of the seashore, which is easily worked and is much used in building.
See Rock, III, (2).
(2) Sand is also a symbol of weight (Job 6:3; Pr 27:3), and
(3) of instability (Mt 7:26).
It is a question what is meant by "the hidden treasures of the sand" in De 33:19.