Now you're thinking out of the box. And that explanation is so obvious, yet so well hidden.
~tin foil hat on~
***
Back to the point, it is the cultural reference in TWOT (©1980) which is rather eye-catching.
Here it is:
616 (chud) [Stg: 2330] propound a riddle. Denominative verb.
PARENT NOUN
616a (chidah) [Stg: 2420] riddle, difficult question, parable.
A derivation has been suggested from Aramaic "hold fast, cover," for the Aramaic achida "riddle" (cf. Daniel 5:12). The chidah is an enigmatic saying, question, or story whose meaning must be determined by the audience.
It is used seventeen times. The KJV translates it nine times as "riddle," five times as "dark" sentences, speeches, or sayings, twice as hard questions," and once as "proverb."
It is used eight times in Judges 14 of "riddles" propounded by Samson to the Philistine guests at his wedding. These were conundrums involving a contest of wits, a source of entertainment popular among Arabs today. Cf. the contest of the guardsmen in 1 Esdras 3: 4-24.
At a higher social level the chidot in 1 Kings 10:1 (2 Chron. 9:1) were "difficult questions" posed by the Queen of Sheba to test Solomon's reputation for wisdom. Josephus (Antiquities 8.5.3 [143]) describes Hiram of Tyre sending Solomon "tricky problems and enigmatic sayings."
The Psalmist in Psalm 49:4 [H 5] speaks of the "riddle" of life, death, and redemption.
In Numbers 12:8 the "dark speeches" denote the indirect revelations ordinarily given by the Lord, in contrast to the face-to-face mode of communication granted to Moses.
See also mashal, which occurs together with chidah in Psalm 49:4 [H 5]; Psalm 78:2; Proverbs 1:6; Ezekiel 17:2; and Habakkuk 2:6.
Bibliography: Rinaldi, G., "Alcuni termini ebraici relativi alla letteratura," Bib 49:274-76.
E.Y.