Numbers 16:28

And Moses said, hereby ye shall know that the Lord hath sent
me to do all these works
To bring the people of Israel out of Egypt, to exchange the firstborn for the Levites, to make Aaron and his sons priests, to give the Levites to them, and to set Elizaphan over the Kohathites, things which these men found fault with, and questioned his authority for doing them:

for [I have] not [done them] of my own mind;
or "not out of my heart" {q}; he had not devised them himself, and done them of his own head, and in any arbitrary way, without the will of God or any authority from him, as these men suggested.