John Mark
Mark 9:39BSB·traditional attribution

“Do not stop him,” Jesus replied. “For no one who performs a miracle in My name can turn around and speak evil of Me.

John Calvin Reformed @genevareformer

39. Forbid him not. Christ did not wish that he should be forbidden; not that he had given him authority, or approved of what he did, or even wished his disciples to approve of it, but because, when by any occurrence God is glorified, we ought to bear with it and rejoice.

Matthew Henry Presbyterian @wholebiblehenry

Here, I. Christ foretels his own approaching sufferings. He passed through Galilee with more expedition than usual, and would not that any man should know of it (Mar 9:30); because he had done many mighty and good works among them in vain, they shall not be invited to see them and have the benefit of them, as they have been.

Commenting on Mark 9:30-40

John Gill Reformed Baptist @doctorgill

But Jesus said, forbid him not,.... Neither him, nor any other they should hereafter meet with, who might be casting out devils in his name, giving this as a reason for it; for there is no man which shall do a miracle in my name; or "miracles", as the Syriac version, as to cast out devils, or heal any sickness and disease, that can lightly...