When God made his promise to Abraham, since there was no one greater for him to swear by, he swore by himself, (NIV) . God, in an oath, made a promise to Abraham and since there was no one greater than God, “He swore by himself”. Here we observe that an oath is a solemn appeal to a deity to witness one’s determination to speak the truth or keep a promise, and in such cases men swear by someone greater and the oath confirms the promise and ends all argument. Further on we read that “Because God wanted to make the unchanging nature of his purpose very clear to the heirs of what was promised, he confirmed it with an oath.” (NIV)  To make the unchanging nature of His purpose very clear to Abraham and all mankind down through the ages He confirmed His promise with an oath. We are thus encouraged by these two unchanging things – God’s promise and His oath – His promise will never fail, it is like an anchor that keeps the ship secure, and our anchor is secured in the “heavenly sanctuary” where our Lord Jesus has entered on our behalf and has become our eternal high priest.
The writer of the Hymn “The Solid Rock” expresses God’s unchanging character and His sure promises, and in this world where we witness so much change in promises made by others, knowing by experience that no one can be trusted, it is so reassuring to know that GOD NEVER CHANGES, NEITHER DOES HIS PROMISES!
“When darkness veils His lovely face,
I rest on His unchanging grace,
In every high and stormy gale
My anchor holds within the veil.
His oath, His covenant, His blood
Support me in the ‘whelming flood
When all around my soul gives way,
He then is all my hope and stay.
On Christ the solid rock I stand,
All other ground is sinking sand
All other ground is sinking sand”
[The Solid Rock by Edward Mote]
Scripture References:  Heb.6:13; Gen 22:16-18;  Heb. 6:17, 20