When he went (en twi elqein auton). Luke's favourite temporal clause = "on the going as to him." That (kai). Another common Lukan idiom, kai=oti after egeneto, like Hebrew wav. They (autoi). Emphatic. Were watching (hsan parathroumenoi). Periphrastic imperfect middle. Note force of autoi, middle voice, and para-. They were themselves watching on the side (on the sly), watching insidiously, with evil intent as in Mark 3:2 (active).