Which by his strength setteth fast the mountains; being girded with power:

Jamieson-Fausset-Brown Bible Commentary

6-13. God's great power and goodness are the grounds of this confidence. These are illustrated in His control of the mightiest agencies of nature and nations affecting men with awe and dread (Ps 26:7; 98:1, &c.), and in His fertilizing showers, causing the earth to produce abundantly for man and beast.

Matthew Henry's Concise Commentary

65:6-13 That Almighty strength which sets fast the mountains, upholds the believer. That word which stills the stormy ocean, and speaks it into a calm, can silence our enemies. How contrary soever light and darkness are to each other, it is hard to say which is most welcome. Does the watchman wait for the morning? so does the labourer earnestly desire the shades of evening. Some understand it of the morning and evening sacrifices. We are to look upon daily worship, both alone and with our families, to be the most needful of our daily occupations, the most delightful of our daily comforts. How much the fruitfulness of this lower part of the creation depends upon the influence of the upper, is easy to observe; every good and perfect gift is from above. He who enriches the earth, which is filled with man's sins, by his abundant and varied bounty, can neither want power nor will to feed the souls of his people. Temporal mercies to us unworthy creatures, shadow forth more important blessings. The rising of the Sun of righteousness, and the pouring forth of the influences of the Holy Spirit, that river of God, full of the waters of life and salvation, render the hard, barren, worthless hearts of sinners fruitful in every good work, and change the face of nations more than the sun and rain change the face of nature. Wherever the Lord passes, by his preached gospel, attended by his Holy Spirit, his paths drop fatness, and numbers are taught to rejoice in and praise him. They will descend upon the pastures of the wilderness, all the earth shall hear and embrace the gospel, and bring forth abundantly the fruits of righteousness which are, through Jesus Christ, to the glory of the Father. Manifold and marvellous, O Lord, are thy works, whether of nature or of grace; surely in loving-kindness hast thou made them all.