See Ps. 78:1-7. Heb. miṣwah, a common word for all God’s requirements, including, to be sure, the moral law. Miṣwah and torah, “law” (see on Num. 19:14), are, for practical purposes, used synonymously.
Whole duty.
The last clause of v. 13 reads, literally, “for this every man.” The word “this” obviously refers to the preceding statement about fearing God and keeping His commandments. The words “duty of” are not in the Hebrew, and the word translated “whole” is attached to the word for “man.” The same Hebrew construction is rendered “every man” in chs. 3:13; 5:19. Solomon here thinks of the recognition of God and obedience to His wise requirements as the supreme objective of life. Paul states the same truth in Acts 17:24-31; Rom. 1:20-23 (see James 2:10-12).
It is man’s duty, his destiny, to obey God, and in so doing he will find supreme happiness. Whatever his lot may be, whether cast in adversity or prosperity, it remains his duty to yield loving obedience to his Maker.