Genesis 27:28

Therefore God give thee of the dew of heaven,.... Or "shall" or "will give thee" x, seeing he was blessed of God, and the blessed seed should spring from him, as well as his posterity should inherit the land of Canaan; for this is said rather by way of prophecy than wish, and so all that follow; and the dew of heaven is the rather mentioned, not only because that makes the earth fruitful on which it plentifully falls, but likewise because the land of Canaan, the portion of Jacob's posterity, much needed it, and had it, for rain fell there but seldom, only twice a year, in spring and autumn; and between these two rains, the one called the former, the other the latter rain, the land was impregnated and made fruitful by plentiful dews; and these signified figuratively both the doctrines and blessings of grace, which all Jacob's spiritual offspring, such as are Israelites indeed, are partakers of, and especially under the Gospel dispensation, see

Deuteronomy 32:2:

and the fatness of the earth, and plenty of corn and wine; and such the land of Canaan was, a fat and fertile land, abounding with all good things, see Deuteronomy 8:8; by which are figured the plenty of Gospel provisions, the word and ordinances, which God has given to his Jacob and Israel in all ages, as he has not given to other people, and especially in the times of the Messiah, Jacob's eminent seed and son, see Psalms 147:19.

x ויתן לך "dabit ergo tibi", Schmidt; so Ainsworth.