Small drops of water produced by the condensation of moisture in the air, of water vapor arising from the ground, and of moisture exuded by plants. The Hebrew word for “dew,” tal, has been defined as “sprinkled moisture” and also signifies “light rain.” (Prov. 3:20) Dew becomes silvery-white, icy hoarfrost when the lower air strata drop in temperature to 32° Fahrenheit. Jehovah is responsible for the dewdrops and is said to scatter the hoarfrost “just like ashes.”—Ps. 147:16; Job 38:28.
Dew forms when night air laden with water vapor cools, depositing the vapor on cooler objects in liquid form. It also develops when warm watery vapor rising from the ground comes in contact with the cooling air. The Bible explains that, early in earth’s history, before it rained on earth, “a mist [vapor] would go up from the earth and it watered the entire surface of the ground.” (Gen. 2:6; compare 1953 edition.) Dew is also produced by plants. In sunlight, moisture from vegetation evaporates into the air, and a plant continues to draw water that has been absorbed by its roots until a balance is obtained between the temperature at the tip of the leaves and that at the plant’s roots. The great amount of dew thus produced by some trees can often be heard dripping from them at night. Most morning dew seems to have this source. Job said, “My root is opened for the waters, and dew itself will stay overnight upon my bough.”—Job 29:19.
In Israel there is normally little if any rain from mid-April to mid-October. However, dew forms and waters the vegetation during these months. The Geography of the Bible says (p. 43): “The value of the dew, which is largely responsible for the growth of grapes during the summer drought, was well appreciated in Biblical times.” Isaiah refers to the “dew in the heat of [grape] harvest.” (Isa. 18:4, 5) After this came the autumn or ‘early’ rains. (Joel 2:23; Jas. 5:7) Night dews in certain areas are so heavy that trees and other plants thereby obtain more than enough moisture to compensate for loss through evaporation during the day. Hence, nocturnal dews may well account for a bountiful harvest where drought and starvation would otherwise prevail.
The importance of dew is emphasized by the discovery that when plants have wilted from dry heat they have recovered more rapidly when dew formed on their leaves at night than they did when the ground was watered. They absorbed so much dew that they functioned normally during the succeeding day without any watering of the ground. The amount of water absorbed from dew and later excreted through the roots into the soil for storage sometimes equaled the plant’s entire weight.
During Israel’s forty-year wilderness trek, the divinely provided manna regularly descended with the dew, remaining upon the earth after the dew’s evaporation. (Ex. 16:13-18; Num. 11:9) By two signs involving dew, Gideon obtained proof of divine support before going forth to fight the Midianites. First, he kept a fleece of wool exposed on a threshing floor overnight, the dew developing only on the fleece while the earth was dry. In the second test, matters were reversed. It is not revealed whether this was the rainless season when dew could be expected.—Judg. 6:36–7:1.
Dew is Scripturally associated with blessing, fertility and abundance. (Gen. 27:28; Deut. 33:13, 28; Zech. 8:12) A return to Jehovah would result in blessing, God saying: “I shall become like the dew to Israel.” (Hos. 14:1, 5) Through Micah, God foretold that “the remaining ones of Jacob” would “become in the midst of many peoples like dew from Jehovah, like copious showers upon vegetation,” foretelling that the remnant of spiritual Jacob (Israel) would be a blessing from God to the people.—Mic. 5:7.
Conversely, lack or the withholding of dew is associated with a disfavored condition. (Gen. 27:39; Hag. 1:10) When God withheld dew and rain from the land of Israel in the days of King Ahab and Elijah, famine resulted.—1 Ki. 17:1; Luke 4:25.
Morning clouds and dew in Israel vanished rapidly in the sun’s heat. What little loving-kindness there was in Ephraim (Israel) and Judah had vanished similarly. (Hos. 6:4) And because of wrongdoing, the inhabitants of Ephraim (Israel) would be taken into captivity, becoming “like the dew that early goes away.”—Hos. 13:1-3, 16.
Dewdrops are quiet and numerous. Perhaps to denote stealthiness or a multitude as numerous as dewdrops, Hushai told Absalom: “We ourselves will be upon [David] just as the dew falls upon the ground.” (2 Sam. 17:12) Jehovah’s King has his “company of young men just like dewdrops,” perhaps as to number.—Ps. 110:3.
Dew is also gentle and refreshing. It is aptly applied to Moses’ farewell prophetic song. (Deut. 32:2) A king’s goodwill is likened to the refreshing effect of dew on vegetation. (Prov. 19:12) The loving unity prevailing among God’s people is refreshing “like the dew of Hermon that is descending upon the mountains of Zion.” Mount Hermon’s forest-covered and perpetually snow-streaked heights caused night vapors to arise that could be carried so far by cold air currents coming down over Hermon from the N that these vapors could condense upon Zion’s mountains many miles to the S.—Ps. 133:1-3.