Exodus 2:11-12

¹¹And it came to pass in those days, when Moses was grown up, that he went out unto his brethren, and looked on their burdens: and he saw an Egyptian smiting a Hebrew, one of his brethren. ¹²And he looked this way and that way, and when he saw that there was no man, he smote the Egyptian, and hid him in the sand.