A.T. Robertson Commentary Mark 8:11

"And the Pharisees came forth, and began to question with him, seeking of him a sign from heaven, trying him." — Mark 8:11 (ASV)

And the Pharisees came forth (κα εξηλθον ο Φαρισαιο). At once they met Jesus and opened a controversy. Matthew 16:1 adds "and Sadducees," the first time these two parties appear together against Jesus. See discussion on Mt 16:1. The Pharisees and Herodians had already joined hands against Jesus in the sabbath controversy . They

began to question with him (ηρξαντο συνζητειν αυτω). Dispute, not mere inquiry, associative instrumental case of αυτο. They began at once and kept it up (present infinitive).