They opened their mouth wide - Gaped upon me to express their contempt.
And said, Aha, aha, our eye hath seen it - They said, האח האח heach, heach, the last syllable in each word being a protracted strongly guttural sound, marking insult and triumph at the same time. It is the word which we translate Ah, Psalm 35:25.
Yea, they opened their mouth wide against me - See the notes at Psalm 22:13.
And said, Aha, aha! - See Psalm 40:15; Psalm 70:3. The language is that which we use when we “detect” another in doing wrong - in doing what he meant to conceal.
Our eye hath seen it - We are not dependent on the reports of others. We have seen it with our own eyes. We have found you out. We cannot be mistaken in regard to it. The reference is to some supposed “detection” of misconduct on the part of David, and the joy and triumph of such a supposed detection.