Once have I sworn by my holiness - That is, once for all; - a single oath - an oath once taken by me - makes it certain. To swear by his "holiness" is to pledge his own holy nature; to make it as certain as that he is holy; to stake the whole question of his holiness on that. That is, If this should not be accomplished - if he should fail in this - it would prove that he was not a holy God.

That I will not lie unto David - Margin, as in Hebrew, "if I lie." The meaning is, He would be found faithful to the promise. See Psalm 89:3-4; compare 2 Samuel 7:8-16.

Once have I sworn - I have made one determination on this head, and have bound myself by my holiness; it is impossible that I should change, and there needs no second oath, the one already made is of endless obligation.

Once have I sworn by my holiness,.... Swearing is ascribed to God after the manner of men, and is done in condescension to the weakness of his people, and to remove doubts and hesitations from them, relating to things spiritual and eternal; as to his everlasting love to them, his covenant with them in Christ, and their perseverance in his grace; and it is made by himself, or one or other of his perfections, as here by his "holiness"; see Amos 4:2, and indeed his holiness being his nature, is no other than he himself, the holy God; and because he could swear by no greater, he sware by himself, that as sure as he was, and was holy, just, and true, he would make good what he promises, Hebrews 6:13 and this is done but once, once for all, that being sufficient; it need not be repeated, nor is it ever revoked; when he swears, he never repents of it, nor changes his mind; and it is to show the immutability of his counsel that he swears at all, Psalm 110:4,

that I will not lie unto David; he will not lie to any, he cannot, it is impossible he should; it would be to deny himself, it is contrary to his being as God, he is not a man that he should lie; it is contrary to his character as the God of truth; he will not lie, neither in his counsel nor covenant, in his purposes nor promises; these are the two immutable things, in which it is impossible he should lie: and he has swore to it that he will not lie to David, to David's son the Messiah, with whom the covenant is made, and stands fast; all the prophecies concerning him he has fulfilled; and all the promises made to him of help and assistance, as man and Mediator, in his work, and of the reward of it, a glory with him, he has made good.

Once have I sworn by my holiness that I will not lie unto David.

that...: Heb. if I lie

35. Once-one thing (Ps 27:4).

by my holiness-as a holy God.

that I will not lie-literally, "if I lie"-part of the form of swearing (1Sa 24:6; 2Sa 3:35).

89:19-37 The Lord anointed David with the holy oil, not only as an emblem of the graces and gifts he received, but as a type of Christ, the King Priest, and Prophet, anointed with the Holy Ghost without measure. David after his anointing, was persecuted, but none could gain advantage against him. Yet all this was a faint shadow of the Redeemer's sufferings, deliverance, glory, and authority, in whom alone these predictions and promises are fully brought to pass. He is the mighty God. This is the Redeemer appointed for us, who alone is able to complete the work of our salvation. Let us seek an interest in these blessings, by the witness of the Holy Spirit in our hearts. As the Lord corrected the posterity of David for their transgressions, so his people shall be corrected for their sins. Yet it is but a rod, not a sword; it is to correct, not to destroy. It is a rod in the hand of God, who is wise, and knows what he does; gracious, and will do what is best. It is a rod which they shall never feel, but when there is need. As the sun and moon remain in heaven, whatever changes there seem to be in them, and again appear in due season; so the covenant of grace made in Christ, whatever alteration seems to come to it, should not be questioned.