I call to remembrance my song in the night: I commune with mine own heart: and my spirit made diligent search. I call to remembrance my song in the night - I do not think that נגינתי neginathi means my song. We know that נגינת neginath signifies some stringed musical instrument that was struck with a plectrum, but here it possibly might be applied to the Psalm that was played on it. But it appears to me rather that the psalmist here speaks of the circumstances of composing the short ode contained in the seventh, eighth, and ninth verses; which it is probable he sung to his harp as a kind of dirge, if indeed he had a harp in that distressful captivity.
My spirit made diligent search - The verb חפש chaphas signifies such an investigation as a man makes who is obliged to strip himself in order to do it; or, to lift up coverings, to search fold by fold, or in our phrase, to leave no stone unturned. The Vulgate translates: "Et scopebam spiritum meum." As scopebam is no pure Latin word, it may probably be taken from the Greek σκοπεω scopeo, "to look about, to consider attentively." It is however used by no author but St. Jerome; and by him only here and in Isaiah 14:23 : And I will sweep it with the besom of destruction; scopabo eam in scopa terens. Hence we see that he has formed a verb from a noun scope, a sweeping brush or besom; and this sense my old Psalter follows in this place, translating the passage thus: And I sweped my gast: which is thus paraphrased: "And swa I sweped my gaste, (I swept my soul), that is, I purged it of all fylth."