This is a pathway of stones, set in rhyme, and sprinkled throughout the King James Bible. Some are serious, some light-hearted. The title includes 'smooth' because rough stones would not have hit the mark, such as the one David picked up, that killed Goliath.
The Bible refers to stones in reference to followers of Christ, like in 1 Peter 2: 4–5
4 …as unto a living stone, disallowed indeed of men, but chosen of God, and precious.
5 Ye, also, as lively stones, are built up into a spiritual house….
It can be noted that stones only become 'smooth' by being knocked about and polished, and that takes rough treatment to remove the sharp edges, so the followers of Christ might expect some rough treatment of their own in order to become 'precious'.