Two is the minimum number of witnesses required to confirm the truth of a report in court (Deuteronomy 19:15; see also Matthew 18:16). The point is not that the Lord has only two witnesses; the point is rather that what these witnesses say (to the Gentiles) is official and the Christ the Judge will reckon with their testimony when he judges the Gentiles for trampling his church underfoot. He, sovereign Lord, has given these witnesses authority to testify of him.
3 And I will grant authority to my two witnesses, and they will prophesy for 1,260 days, clothed in sackcloth.”