Genesis 47:31

To the bed's head. St. Paul, (Hebrews xi. 21,) following the Greek translation of the Septuagint, reads adored the top of his rod. Where note, that the same word in the Hebrew, according to the different pointing of it, signifies both a bed and a rod. And to verify both these sentences, we must understand that Jacob, leaning on Joseph's rod, adored, turning towards the head of his bed: which adoration, inasmuch as it was referred to God, was an absolute, and sovereign worship: but inasmuch as it was referred to the rod of Joseph, as a figure of the sceptre, that is, of the royal dignity of Christ, was only an inferior and relative honour. (Challoner)

St. Augustine proposes another very probable explanation. He adored God, supporting himself on the top of his staff, or of Joseph's sceptre, q. 162. The Septuagint and Syriac intimate, that Jacob bowed down respectfully towards the sceptre of his son, and thus complied with the explication which he had given to his dream, chap. xxxvii. 10. Others, who understood the Hebrew Hamitta, in the sense given to it by St. Jerome, Aquila, and Symmachus, suppose that after he had given his last instructions to Joseph in a sitting posture, growing weaker, he laid his head again upon his pillow. (Calmet)

God was pleased to have this recorded in a language subject to such various interpretations; as he, perhaps, would have us to understand, that Jacob literally bowed down both to the bed-head and to the top of the sceptre. For many believe, that the Scripture has often several literal meanings. (Tirinus)