Luke 20:5-7 NIV

5 They discussed it among themselves and said, “If we say, ‘From heaven,’ he will ask, ‘Why didn’t you believe him?’
6 But if we say, ‘Of human origin,’ all the people will stone us, because they are persuaded that John was a prophet.”

References for Luke 20:6

7 So they answered, “We don’t know where it was from.”