Mark 11:31

31 They argued among themselves, "If we say, ‘It's of heavenly origin,' he'll say, ‘Then why didn't you believe him?'

Mark 11:31 Meaning and Commentary

Mark 11:31

And they reasoned with themselves saying
Privately; perhaps, they withdrew at a little distance for a short time, and consulted among themselves what answer to return; and the amount of their reasonings were this;

if we shall say from heaven, he will say, why then did ye not
believe him?
that is, should they say that John had a divine commission for what he said and did, they were aware that Christ would reply, why did not ye give credit to him? and had you done so, seeing he testified of me, you would have had no occasion to have put the above question; (See Gill on Matthew 21:25).

Mark 11:31 In-Context

29 Jesus said to them, "I have a question for you. Give me an answer, then I'll tell you what kind of authority I have to do these things.

30 Was John's baptism of heavenly or of human origin? Answer me."

31 They argued among themselves, "If we say, ‘It's of heavenly origin,' he'll say, ‘Then why didn't you believe him?'

32 But we can't say, ‘It's of earthly origin.'" They said this because they were afraid of the crowd, because they all thought John was a prophet.

33 They answered Jesus, "We don't know." Jesus replied, "Neither will I tell you what kind of authority I have to do these things."