Mark 11:31

31 They argued with one another, "If we say, "From heaven,' he will say, "Why then did you not 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 will ask you one question; answer me, and I will tell you by what authority I do these things.
30 Did the baptism of John come from heaven, or was it of human origin? Answer me."
31 They argued with one another, "If we say, "From heaven,' he will say, "Why then did you not believe him?'
32 But shall we say, "Of human origin'?"—they were afraid of the crowd, for all regarded John as truly a prophet.
33 So they answered Jesus, "We do not know." And Jesus said to them, "Neither will I tell you by what authority I am doing these things."
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.