What kind of pit was David in? (Psalm 40:2)

Psalm 40 New International Version (NIV)
Psalm 40[a]
For the director of music. Of David. A psalm.
1 I waited patiently for the Lord;
    he turned to me and heard my cry.
2 He lifted me out of the slimy pit,
    out of the mud and mire;
he set my feet on a rock
    and gave me a firm place to stand.

Footnotes:
a.  Psalm 40:1 In Hebrew texts 40:1-17 is numbered 40:2-18.

Clarify • Share • Report • Asked May 07 2019 • Jack Gutknecht