And he sighed deeply in his Spirit
In his human soul; and which shows that he had one, and was subject to grief and sorrow, and all passions and infirmities, excepting sin. This deep sigh was on account of the hardness of their hearts, the malignity of their minds, and insincerity of their intentions; who had no view to come at truth by this inquiry, but to ensnare him:
and saith, why doth this generation seek after a sign?
when so many have been shown among them, and they will not believe:
verily I say unto you, there shall no sign be given to this
such as they desired; namely, one from heaven. The Evangelist Matthew adds, "but the sign of the Prophet Jonas"; (See Gill on Matthew 16:4), (See Gill on Matthew 12:40).