How did the Bible know?
Psalm 22:16 "The congregation of the wicked has enclosed Me. They pierced My hands and My feet"
This prophecy was written over 1000 yrs before the cross. In fact, crucifixion wasnt even close to being invented yet. How does the Bible know this? The people were able to surround Him as He hung on the cross. The process of the punishment of crucifixion was nailing ones hands and feet to the cross. Again, this wasnt even an option until really the Roman Empire perfected this capital punishment.