The Request for a Sign Refused. The Pharisees require some special authentication from Jesus beyond exorcisms and healings. They are said to tempt Jesus either because their question was intended to embarrass, or because unintentionally (like Peter in Mark 8:33) they renewed what had been one of the three great temptations (Matthew 4:5-7). Mk. alone records the emotion of Jesus. He sighed in spirit. This question and answer are clearly historical, and may have been taken by Mk. from Q. The warning against the leaven of the Pharisees naturally follows.
Related Commentaries of Mark 8:11
Mark 8:11-13
11 And the Pharisees came forth, and began to question with him, seeking of him a sign from heaven, tempting him.
12 And he sighed deeply in his spirit, and saith,Why doth this generation seek after a sign? verily I say unto you, There shall no sign be given unto this generation.
13 And he left them, and entering into the ship again departed to the other side.