God's promise

From the additional notes to Charles Spurgeon's The Treasury of David, on Psalm 118, verse 76

Let, I pray thee, thy merciful kindness be for my comfort, according to thy word unto thy servant.

If his promise did not please him, why did he [God] make it? If our reliance on the promise did not please him, why did his goodness work it? It would be inconsistent with his goodness to mock his creature, and it would be the highest mockery to publish his word, and create a temper in the heart of his supplicant suited to his promise, which he never intended to satisfy. He can as little wrong his creature as wrong himself, and therefore he can never disappoint that faith which after his own methods casts itself into the arms of his kindness, and is his own workmanship, and calls him author. That goodness which imparted itself so freely to the irrational creation will not neglect those nobler creatures that put their trust in him. This renders God a fit object for trust and confidence. — Stephen Charnock.