They feared the crowd

Jesus and his disciples returned once more to Jerusalem.
As he was walking in the temple area,
the chief priests, the scribes, and the elders
approached him and said to him,
"By what authority are you doing these things?
Or who gave you this authority to do them?"
Jesus said to them, "I shall ask you one question.
Answer me, and I will tell you by what authority I do these things.
Was John's baptism of heavenly or of human origin? Answer me."
They discussed this among themselves and said,
"If we say, 'Of heavenly origin,' he will say,
'Then why did you not believe him?'
But shall we say, 'Of human origin'?"–
they feared the crowd,
for they all thought John really was a prophet.
So they said to Jesus in reply, "We do not know."
Then Jesus said to them,
"Neither shall I tell you by what authority I do these things."
(Mk 11:27-33)