Shachat is the pit. The lexicons build the noun from shuach, to sink down, and the poets set it in parallel with Sheol as the hole a life disappears into: "You will not abandon my nefesh to Sheol; You will not let Your faithful one see shachat" (Psalms 16:10). Yonah prays its reversal from inside the fish: "You brought up my life from shachat" (Jonah 2:6). Job's angel-song runs a man down to the pit and back three times in one speech (Job 33:28-30).

The English tradition split at this word. The KJV printed "corruption" in Psalm 16, following the Septuagint's diaphthora, which heard the related verb "to ruin" inside the noun; the JPS and most modern Jewish translations print "the Pit," following the parallelism with Sheol. Name both honestly: decay describes what the pit does, the pit is what the psalm says.

And here is the quiet wonder: the two readings collapse into one at the only grave that ever gave back its dead. The faithful one went down to the place of sinking and was not left there, and neither the pit nor its decay received what it was owed. Read it either way and the psalm keeps its promise.