A.T. Robertson Commentary Acts 23:13

"And they were more than forty that made this conspiracy." — Acts 23:13 (ASV)

More than forty (πλειους τεσσερακοντα). Without "than" (η) as in verse 21; 24:11 and often in the ancient Greek.

Conspiracy (συνωμοσιαν). Old word from συνομνυμ, to swear together. Only here in the N.T.