Exodus 2:11-12 KJV

11 And it came to pass in those days, when Moses was grown, that he went out unto his brethren, and looked on their burdens: and he spied an Egyptian smiting an Hebrew, one of his brethren.

12 And he looked this way and that way, and when he saw that there was no man, he slew the Egyptian, and hid him in the sand.