But know - This is addressed to those whom, in the previous verse, he had called the “sons of men;” that is, his foes. This is designed to show them that their opposition to him must be vain, since God had determined to set him apart for his own service, and would, therefore, hear his prayer for relief and protection.
That the Lord hath set apart - That Yahweh had done this; that is, that he had designated him to accomplish a certain work, or that he regarded him as an instrument to perform it. He would, therefore, protect him whom he had thus appointed; and their efforts were really directed against Yahweh himself, and must be vain.
Him that is godly for himself - For his own purposes, or to accomplish his own designs. The reference is here undoubtedly to the psalmist himself; that is, to David. The word “godly,” as applied to himself, is probably used in contrast with his enemies as being engaged in wicked designs, to wit, in rebellion, and in seeking to dispossess him of his lawful throne. The psalmist felt that his cause was a righteous cause, that he had done nothing to deserve this treatment at their hands; and that he had been originally exalted to the throne because God regarded him as a friend of himself and of his cause; and because he knew that he would promote the interests of that cause. The word here rendered “godly,” חסיד châsı̂yd, is derived from חסד chesed, which means desire, ardor, zeal; and then kindness, benignity, love toward God or man. Here the word properly denotes one who has love to God, or one who is truly pious; and it is correctly rendered “godly.” Compare Psalms 30:4-5; Psalms 31:23; Psalms 37:28. The idea is, that as God had appointed him for his own great purposes, the real aim of the rebels was to oppose Yahweh; and the purposes in which they were engaged could not, therefore, be successful.
The Lord will hear when I call unto him - As I am engaged in his service; as I am appointed to accomplish a certain purpose for him, I may confidently believe that he will hear me, and will deliver me out of their hands. Is not this always the true ground of encouragement to pray - that if God has a purpose to accomplish by us he will hear our prayer, and save us from danger, and deliver us out of the hand of our enemies? And should not this be the main design in our prayers - that God “would” thus spare us that we may accomplish the work which he has given us to do?