Because he hath loosed my cord, and afflicted me, they have also let loose the bridle before me. Because he hath loosed my cord - Instead of יתרי yithri, my cord, which is the keri or marginal reading, יתרו yithro, his cord, is the reading of the text in many copies; and this reading directs us to a metaphor taken from an archer, who, observing his butt, sets his arrow on the string, draws it to a proper degree of tension, levels, and then loosing his hold, the arrow flies at the mark. He hath let loose his arrow against me; it has hit me; and I am wounded. The Vulgate understood it in this way: Pharetram enim suam aperuit. So also the Septuagint: Ανοιξας γαρ φαρετραν αυτου; "He hath opened his quiver."
They have also let loose the bridle - When they perceived that God had afflicted me, they then threw off all restraints; like headstrong horses, swallowed the bit, got the reins on their own neck, and ran off at full speed.