Bible's New Testament has applied multiple levels of witnesses.
"..at the mouth of two witnesses, or at the mouth of three witnesses, shall the matter be established." - Deut 19:15, Mat 18:16
The pic shows how the NT has the idea of '2 or 3 witnesses are required to establish fact' (which is an O.T. rule) woven into the fabric of the NT at multiple levels.
e.g.
- 3 events showing Jesus' divinity, (e.g. when Jesus transfigured into light)
- and there were specifically 3 witnesses present(Peter,James,John),
- and that account was written about in 3 gospel books,
- and 2 of those present(Peter,John) write about Him and have their books added to the NT.
e.g.
- He died on the cross
- and there were 3+ witnesses present,
- and that account was written about in 4 gospel books,
- and 2 of those present(Peter,John) write about Him and have their books added to the NT.