This verse seems strangely short—it consists of only four words in the Hebrew, Probably something like "his weapons," or "the weapons of death" (Psalms 7:13), has fallen out. Restore them, and the verse becomes a two-membered one, like its companions.
To enter into my reins. So Job (Job 16:12), "He cleaveth my reins asunder." "Reins," equivalent to "inward parts," like "heart," with which it is often combined; e.g. Jeremiah 11:20; Jeremiah 17:10; Jeremiah 20:12.