William Burkitt on James 1:25

Observe here, 1. The title given to the word of God, particularly the gospel, it is called liberty, a law of liberty, and a perfect law of liberty: partly because it calleth us to a state of liberty and freedom, and teacheth us the way to true liberty, and offers us the assistance of a spirit of liberty; partly because it spareth none, but dealeth with all persons freely, without respect of persons; the gospel, or word of God, then is a law of liberty.

Observe, 2. The duty here required, with reverence to this law of liberty, namely, to look into it, and continue therein, to look into it with an accurate and narrow inspection, as the disciples did into Christ's sepulchre, and as the angels look into the mysteries of salvation, 1Pe 1:12. To look into the law of liberty, implies deepness of mediation, and liveliness of impression; and continuing therein, imports perseverance in the knowlege, faith and obedience of the gospel, in order to our fruitfulness in good works: If ye abide in me, and my word abide in you, says Christ, ye shall bring forth much fruit, Joh 15:5,7.

Observe, 3. The reward promised and insured to such as look into the gospel, that law of liberty, that continue in it, and are doers of the work required by it, they are blessed in their deed; there is a blessedness annexed to the doing of that work which the word of God requires; yet mark the distinctness of Scripture phrase; the apostle doth not say, that the doers of the word shall be blessed for their deed; but in the deed it is an evidence of our blessedness, not the ground of it, the way, though not the cause of blessedness.