I love the conversations between Moses and God. They seem so honest and real, Moses doesn't seem to hold back his true thoughts.
When God sends Moses to speak to Pharaoh, and God keeps explaining to Moses how He will provide for Moses' needs, Moses finally reveals his true thoughts in Exodus 4:13 - “Oh, my Lord, please send someone else.”
And in Exodus 6:30, Moses says to God "Behold, I am of uncircumcised lips, and how shall Pharaoh hearken unto me?” Ewww. Moses and Zipporah seemed to have some marital problems - maybe the state of his lips was a contributor?
And finally, when God was explaining to Moses how He was enough in Numbers 11:23: “Is the Lord’s arm too short? Now you will see whether or not what I say will come true for you.”