How can we understand the altar's construction without man's tools?
Answered in 1 source
The altar was to be made of whole stones, symbolizing that salvation is entirely God's work, unmarred by human merit.
The instruction that the altar at Ebal be built without the use of man-made tools emphasizes a key theological principle in Reformed theology: salvation is entirely the work of God. In Exodus 20:25, God specified that no tool should touch the stones used for the altar, symbolizing that human effort or merit contributes nothing to the work of salvation. This teaches us that the effectiveness of the altar and the sacrifices made upon it stems solely from God's design and purpose, reflecting the truth that our salvation is not based on our righteousness but entirely on Christ's perfect merit.
Commentary