Give glory, etc. Let your tribute to your King be that of humble submission to his will. The precise application of the phrase must be derived from the context (comp. Joshua 7:19; Malachi 2:2). Upon the dark mountains; rather, upon mountains of twilight.
A "mountain" is an image of a great obstacle (Zechariah 4:7; Matthew 21:21). As Judah is walking along, the hitherto even tenor of his way gives place to huge mountains wrapped in an impenetrable dusk, over which he will stumble and fall if he does not repent in time.