Luke 20:5 Meaning

3And he answered and said unto them, I will also ask you one thing; and answer me:

4The baptism of John, was it from heaven, or of men?

5And they reasoned with themselves, saying, If we shall say, From heaven; he will say, Why then believed ye him not?

6But and if we say, Of men; all the people will stone us: for they be persuaded that John was a prophet.

7And they answered, that they could not tell whence it was.