John Trapp on Psalms 78:2

Verſ. 2. I will open my mouth in a parable] I will ſpeak freely and plainly (I will open my mouth, Mat. 5.2. Act. 10.34.) and yet acutely and accurately, See Pſal. 49.4. with the Note.

I will utter dark ſayings of old] Heb. I will wel-out (as from a ſpring or fountain) dark or ſharp ſayings, tranſacted and recorded of old, but of good uſe for ever. Difficulty doth not diſcourage, but rather whet on heroick ſpirits to a more diligent inquiry. Aben-Ezra noteth here, that verſe 9. The children of Ephraim, &c. is a parable, and verſe 25. Man did eat Angels food, is a riddle, or dark ſaying.