Moses
Numbers 32:15ESV·traditional attribution

For if you turn away from following him, he will again abandon them in the wilderness, and you will destroy all this people.”

John Gill Reformed Baptist @doctorgill

And they came near unto him,.... The heads of the tribes of Gad and Reuben came a little nearer to Moses, having something more to say unto him, in order to explain their meaning, and in doing which they used some degree of freedom and boldness with him, see Gen 44:18.

Geneva Bible Notes Reformed @genevanotes

For if ye turn away from after him, he will yet again leave them in the wilderness; and ye shall destroy all this people. (d) By your occasion.

Keil & Delitzsch Lutheran @keilanddelitzsch

Num 32:15 “If ye draw back behind Him,” i.e., resist the fulfilment of the will of God, to bring Israel to Canaan, “He will leave it (Israel) still longer in the desert, and ye prepare destruction for all this nation.”