21. both the sons--Greek, "each of the sons" (Ge 47:29; 48:8-20). He knew not Joseph's sons, and could not distinguish them by sight, yet he did distinguish them by faith, transposing his hands intentionally, so as to lay his right hand on the younger, Ephraim, whose posterity was to be greater than that of Manasseh: he also adopted these grandchildren as his own sons, after having transferred the right of primogeniture to Joseph (Ge 48:22).
      and worshipped--This did not take place in immediate connection with the foregoing, but before it, when Jacob made Joseph swear that he would bury him with his fathers in Canaan, not in Egypt. The assurance that Joseph would do so filled him with pious gratitude to God, which he expressed by raising himself on his bed to an attitude of worship. His faith, as Joseph's (Heb 11:22), consisted in his so confidentially anticipating the fulfilment of God's promise of Canaan to his descendants, as to desire to be buried there as his proper possession.
      leaning upon the top of his staff-- Ge 47:31, Hebrew and English Version, "upon the bed's head." The Septuagint translates as Paul here. JEROME justly reprobates the notion of modern Rome, that Jacob worshipped the top of Joseph's staff, having on it an image of Joseph's power, to which Jacob bowed in recognition of the future sovereignty of his son's tribe, the father bowing to the son! The Hebrew, as translated in English Version, sets it aside: the bed is alluded to afterwards (Ge 48:2; 49:33), and it is likely that Jacob turned himself in his bed so as to have his face toward the pillow, Isa 38:2 (there were no bedsteads in the East). Paul by adopting the Septuagint version, brings out, under the Spirit, an additional fact, namely, that the aged patriarch used his own (not Joseph's) staff to lean on in worshipping on his bed. The staff, too, was the emblem of his pilgrim state here on his way to his heavenly city (Heb 11:13, 14), wherein God had so wonderfully supported him. Ge 32:10, "With my staff I passed over Jordan, and now I am become," &c. (compare Ex 12:11; Mr 6:8). In 1Ki 1:47, the same thing is said of David's "bowing on his bed," an act of adoring thanksgiving to God for God's favor to his son before death. He omits the more leading blessing of the twelve sons of Jacob; because "he plucks only the flowers which stand by his way, and leaves the whole meadow full to his readers" [DELITZSCH in ALFORD].

JFB.