Man's goings are of the LORD; how can a man then understand his own way?
Man's (Hebrew, gaaber (H1397 ): a mighty man's) goings (are) of the Lord. Whatever success attends mighty warriors, as Julius Caesar, Alexander, Napoleon, etc., is entirely due to the Lord.
How can a man ( 'aadaam (H120 ): man in general) then understand his own way? As the former clause attributes to the Lord exclusively the ordering of great men's goings, in order to attain success; so this clause attributes to Him, to the exclusion of man, the prescient understanding of man's course. God directs natural actions by ordinary providence, spiritual actions by His special providence, which foreordains from eternity, awakens the sinner, removes obstacles, suggests that state of life wherein He foresees that the man will not fall away, but attain to glory. However a man may understand his way in respect to its beginning and aim, yet he understands not the best means in doubtful cases, nor can he ensure the issue. We ought therefore to call upon God in all our undertakings, for His overruling guidance, and not trust in our own sagacity.