Verses 13 through 17 are the rich blessing concerning Joseph.
Moses blessed Joseph by saying that his land would be blessed by Jehovah with the choicest things of heaven, with the dew and with the deep waters that couch beneath; with the choicest of the crops of the sun and with the choicest of the yield of the moons; with the top of the ancient mountains and with the choicest things of the eternal hills; with the choicest things of the earth and the fullness thereof, and the favor of Him who dwelt in the bush (vv. 13-16a). The expression "Him who dwelt in the bush" refers to God, who in Exodus 3 appeared to Moses from within a burning bush. Moses asked that all these blessings would come upon the head of Joseph and upon the top of him who is separate among his brothers (Deut. 33:16b). Joseph was separated from his brothers and taken to Egypt in order to fulfill God's purpose.
Like his firstborn bullock, Joseph would have majesty, and his horns would be the horns of the wild ox (v. 17a). With these horns he would drive peoples, the ends of the earth together (v. 17b).
Verse 17c says, "Those are the ten thousands of Ephraim; /And those the thousands of Manasseh." Ephraim and Manasseh were the two sons of Joseph. The fact that they are mentioned here indicates that the tribe of Joseph would eventually receive a double portion, which is part of the birthright of the firstborn son. Reuben lost the birthright, but a part of it—the double portion of the land—went to Joseph. The kingship went to Judah, and the priesthood, to Levi.
Verses 18 and 19 are the blessing concerning Zebulun and Issachar. Verse 18 says, "Rejoice, Zebulun, for your going forth, /And Issachar, for your tents!" This going forth was fulfilled in the Lord's sending forth the apostles. Most of the apostles, who were sent forth to disciple the nations, were produced from Zebulun, which was in the region of Galilee.
Zebulun and Issachar would call peoples to the mountain. There these tribes would offer sacrifices of righteousness; for they would suck the abundance of the seas and the hidden treasures of the sand (v. 19). This indicates that Zebulun and Issachar would be close to the sea.
In verses 20 and 21 Moses blessed the tribe of Gad. Because Gad was rather small, Moses said, "Blessed be He who enlarges Gad" (v. 20a). God is the One who would enlarge this tribe, which would be strong in fighting. This is indicated by the words, "He dwells as a lioness, /And tears off the arm, yea, even the top of the head" (v. 20b).
Gad provided the first part of the land for himself, for there the portion of a lawgiver is reserved (v. 21a). Moreover, he came with the heads of the people and executed the righteousness of Jehovah and His judgments with Israel (v. 21b). This indicates that some among the people of Gad had the knowledge of God's law and His judgments.