I will observe thy statutes In these words he avers it to be his intention to observe the law of God, but, conscious of his own weakness, he utters a prayer that God would not deprive him of his grace. The term forsake is susceptible of two interpretations, either that God withdraws his Spirit, or that he permits his people to be brought low by adversity, as if he had forsaken them. The latter interpretation agrees best with the context, and is most in accordance with the phrase immediately subjoined, very far The prophet is not altogether averse to the trial of his faith, only he is apprehensive lest it might fail were the trial to be too long protracted, and therefore he desires to be treated with tenderness in his infirmity.,' O God! thou sees my frame of mind, and, as I am but a man, do not conceal too long from me the tokens of thy favor, or defer helping me longer than is proper for me, lest, imagining myself to be forsaken of thee, I turn aside from the direct pursuit of godliness."

I will keep thy statutes - Thy commands; thy laws. This expresses the firm purpose of the psalmist, He meant to keep the law of God; he could confidently say that he would do it - yet coupled with the prayer which follows, that God would not forsake him.
O forsake me not utterly - Hebrew, "To very much;" so as to leave me to myself. His confidence that he would keep the commandments of God was based on the prayer that God would not leave him. There is no other ground of persuasion that we shall be able to keep the commandments of God than that which rests on the belief and the hope that He will not leave us.

O forsake me not utterly - עד מאד ad meod, "to utter dereliction;" never leave me to my own strength, nor to my own heart!

I will keep thy statutes: O forsake me not (f) utterly.
(f) He does not refuse to be tried by temptations, but he fears to faint, if God does not help his infirmity in time.

I will keep thy statutes,.... This is a resolution taken up in the strength of divine grace, to answer the end of learning the judgments of God; which he did, not merely to have a notional knowledge of them, but to put them in practice; and not that he thought he could perfectly keep them, but was desirous of observing them in the best manner he could, as assisted by the grace of God; from love to God, in the faith and name of Christ, and with a view to the glory of God; without dependence upon them for life and salvation;
O forsake me not utterly; totally and finally, or not at all; otherwise as if he should say, I shall never be able to keep thy statutes; so sensible was he of the necessity of the divine Presence and grace, to assist him in the observance of them: or, "for ever", as Ben Balaam interprets it, and so the Ethiopic version; R. Moses reads the words, "O forsake me not", in a parenthesis, and joins the rest thus, "I will keep thy statutes vehemently"; or with all my strength and might; and so Kimchi reads them: but such an interpretation is very forced, and contrary to the accents.

Recognizes the need of divine grace.

Forsake me not - For then I shall fall into the foulest sins.