Exodus 2:11-12

11Now it came about in those days, 1when Moses had grown up, that he went out to his brethren and looked on their 23hard labors; and 4he saw an Egyptian beating a Hebrew, one of his brethren.

12So he 5looked this way and that, and when he saw there was no one around, he 6struck down the Egyptian and hid him in the sand.