Even by the God of thy father, who shall help thee; and by the Almighty, who shall bless thee with blessings of heaven above, blessings of the deep that lieth under, blessings of the breasts, and of the womb: The God of thy father - How frequently God is called the God of Jacob none needs be told who reads the Bible.
God All-sufficient - Instead of את שדי Eth Shaddai, The Almighty or All-sufficient; I read אל שדי El Shaddai, God All-sufficient; which is the reading of the Samaritan, Septuagint, Syriac, and Coptic, and of three reputable MSS. In the collections of Kennicott and De Rossi. The copies used by those ancient versions had evidently אל El, God, and not את eth, The, a mistake produced in later times. On the word אל שדי El Shaddai, See Clarke on Genesis 17:1 (note).
The blessing of the heavens from above - A generally pure, clear, serene sky, frequently dropping down fertilizing showers and dews, so as to make a very fruitful soil and salubrious atmosphere.
Blessings lying in the deep beneath - Whatever riches could be gained from the sea or rivers, from mines and minerals in the bowels of the earth, and from abundant springs in different parts of his inheritance. Our translation of this line is excessively obscure: Blessings of the deep that lieth under. What is it that lies under the deep: By connecting ברכת bircoth, blessings, with רבצת robetseth, lying, all ambiguity is avoided, and the text speaks a plain and consistent sense.
The blessings of the breasts and of the womb - A numerous offspring, and an abundance of cattle. The progeny of Joseph, by Ephraim and Manasseh, amounted at the first census or enumeration (Numbers 1). to 75,900 men, which exceeded the sum of any one tribe; Judah, the greatest of the others, amounting to no more than 74,600. Indeed, Ephraim and Manasseh had multiplied so greatly in the days of Joshua, that a common lot was not sufficient for them. See their complaint, Joshua 17:14.