A.T. Robertson Commentary Matthew 22:34

"But the Pharisees, when they heard that he had put the Sadducees to silence, gathered themselves together." — Matthew 22:34 (ASV)

He had put the Sadducees to silence (εφιμωσεν τους Σαδδουκαιους). Muzzled the Sadducees. The Pharisees could not restrain their glee though they were joining with the Sadducees in trying to entrap Jesus.

Gathered themselves together (συνηχθησαν επ το αυτο). First aorist passive, were gathered together. Επ το αυτο explains more fully συν-. See also Ac 2:47. "Mustered their forces" (Moffatt).