Have I not promised, and will I not fulfill

[Guest]

I encountered a gentleman that was singing this chorus to anyone and everyone in the store where I work. I would like to know the name of the song if anyone knows. The chorus is:

Have I not promised, and will I not fulfill
Every promise I have give'n in My precious will.
I am the Lord the God, and I hear thy faintest cry,
I will never, no never, My promises deny.