Mark 11:31

31 And they reasoned with themselves, saying, If we should say, Of heaven, he will say, Why [then] have ye not believed 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 And Jesus answering said to them, *I* also will ask you one thing, and answer me, and I will tell you by what authority I do these things:

30 The baptism of John, was it of heaven, or of men? answer me.

31 And they reasoned with themselves, saying, If we should say, Of heaven, he will say, Why [then] have ye not believed him?

32 but should we say, Of men -- they feared the people; for all held of John that he was truly a prophet.

33 And they answering say to Jesus, We do not know. And Jesus [answering] says to them, Neither do *I* tell you by what authority I do these things.