Charles H. Spurgeon on Psalms 40:2

An horrible pit; or, as it is in the Hebrew, a pit of noise; so called because of waters that falling into it with great violence, make a roaring dreadful noise; or because of the strugglings and outcries they make that are in it; or because when anything is cast into deep pits, it will always make a great noise; and where he stuck fast in miry clay, without seeming possibility of getting out. And some refer this to the greatness of Christ's terrors and sufferings, and his deliverance from them both. Arthur Jackson.