So when God wanted to make the unchanging nature of His purpose very clear to the heirs of the promise, He guaranteed it with an oath.
Cross References
Psalm 110:4The LORD has sworn and will not change His mind: "You are a priest forever in the order of Melchizedek."
Proverbs 19:21Many plans are in a man's heart, but the purpose of the LORD will prevail.
Ephesians 1:11In Him we were also chosen as God's own, having been predestined according to the plan of Him who works out everything by the counsel of His will,
Hebrews 6:18Thus by two unchangeable things in which it is impossible for God to lie, we who have fled to take hold of the hope set before us may be strongly encouraged.
Hebrews 11:9By faith he dwelt in the promised land as a stranger in a foreign country. He lived in tents, as did Isaac and Jacob, who were heirs with him of the same promise.
Treasury of Scripture
Wherein God, willing more abundantly to show to the heirs of promise the immutability of his counsel, confirmed it by an oath:
more.
Psalm 36:8
They shall be abundantly satisfied with the fatness of thy house; and thou shalt make them drink of the river of thy pleasures.
Song of Solomon 5:1
I am come into my garden, my sister, my spouse: I have gathered my myrrh with my spice; I have eaten my honeycomb with my honey; I have drunk my wine with my milk: eat, O friends; drink, yea, drink abundantly, O beloved.
Isaiah 55:7
Let the wicked forsake his way, and the unrighteous man his thoughts: and let him return unto the LORD, and he will have mercy upon him; and to our God, for he will abundantly pardon.
the heirs.
Hebrews 6:12
That ye be not slothful, but followers of them who through faith and patience inherit the promises.
Hebrews 11:7,9
By faith Noah, being warned of God of things not seen as yet, moved with fear, prepared an ark to the saving of his house; by the which he condemned the world, and became heir of the righteousness which is by faith…
Romans 8:17
And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together.
the immutability.
Hebrews 6:18
That by two immutable things, in which it was impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us:
Job 23:13,14
But he is in one mind, and who can turn him? and what his soul desireth, even that he doeth…
Psalm 33:11
The counsel of the LORD standeth for ever, the thoughts of his heart to all generations.
confirmed it.
Hebrews 6:16
For men verily swear by the greater: and an oath for confirmation is to them an end of all strife.
Genesis 26:28
And they said, We saw certainly that the LORD was with thee: and we said, Let there be now an oath betwixt us, even betwixt us and thee, and let us make a covenant with thee;
Exodus 22:11
Then shall an oath of the LORD be between them both, that he hath not put his hand unto his neighbour's goods; and the owner of it shall accept thereof, and he shall not make it good.
