Put forth a riddle, etc. Again there is an interval of silence, till another theme is suggested to the prophet's mind and worked out elaborately. This he describes as a "riddle" (same word as the "dark speeches" of Numbers 12:8, the "hard questions" of 1 Kings 10:1).
It will task the ingenuity of his hearers or readers to interpret it, and so he subjoins (Ezekiel 17:12-24) the interpretation. That interpretation enables us to fix the occasion and the date of the prophecy.
It was the time when Zedekiah was seeking to strengthen himself against Nebuchadnezzar by an Egyptian alliance.