Genesis 47:31

31.And Israel bowed himself upon the bed’s head. By this expression, Moses again affirms that Jacob esteemed it a singular kindness, that his son should have promised to do what he had required respecting his burial. For he exerts his weak body as much as he is able, in order to give thanks unto God, as if he had obtained something most desirable. He is said to have worshipped towards the head of his bed: because, seeing he was quite unable to rise from the bed on which he lay, he yet composed himself with a solemn air in the attitude of one who was praying. The same is recorded of David (1 Kings 1:47) when, having obtained his last wish, he celebrates the grace of God. The Greeks have translated it, at the top of his staff: which the Apostle has followed in the Epistle to the Hebrews, (Hebrews 11:21.) And though the interpreters seem to have been deceived by the similitude of words; because, with the Hebrews, מוטה (mitah) signifies “bed,” מוטה (motah,) “a staff;” yet the Apostle allows himself to cite the passage as it was then commonly used, lest he might offend unskillful readers, without necessity. (190) Moreover, they who expound the words to mean that Jacob worshipped the scepter of his son, absurdly trifle. The exposition of others, that he bowed his head, leaning on the top of his staff, is, to say the least, tolerable. But since there is no ambiguity in the words of Moses, let it suffice to keep in memory what I have said, that, by this ceremony, he openly manifested the greatness of his joy.