A.T. Robertson Commentary Mark 11:31

"And they reasoned with themselves, saying, If we shall say, From heaven; He will say, Why then did ye not believe him?" — Mark 11:31 (ASV)

If we say (εαν ειπωμεν). Third-class condition with aorist active subjunctive. The alternatives are sharply presented in their secret conclave. They see the two horns of the dilemma clearly and poignantly. They know only too well what Jesus will say in reply. They wish to break Christ's power with the multitude, but a false step now will turn the laugh on them. They see it.