Moses
Numbers 16:16ESV·traditional attribution

And Moses said to Korah, “Be present, you and all your company, before the LORD, you and they, and Aaron, tomorrow.

John Calvin Reformed @genevareformer

16. And Moses said unto Korah. The idea of Moses is not to make an experiment as if in a doubtful matter; but, being assured by the Spirit of prophecy what the event would be, he summons Korah before the tribunal of God, that he may receive the sentence of condemnation which he deserves.

Matthew Henry Presbyterian @wholebiblehenry

Here is, I. The insolence of Dathan and Abiram, and their treasonable remonstrance. Moses had heard what Korah had to say, and had answered it; now he summons Dathan and Abiram to bring in their complaints (Num 16:12); but they would not obey his summons, either because they could not for shame say that to his face which they were resolved to say, and then...

Commenting on Numbers 16:12-22

John Gill Reformed Baptist @doctorgill

And Moses said unto Korah,.... Who was still with him, when the messenger returned from Dathan and Abiram, and who heard what Moses said in his own defence: be thou and all thy company before the Lord; at the tabernacle, at the door of it; the Targum of Jonathan is, at the house of judgment, the court of judicature, where this affair was to be...