2 Samuel 14:6
"And thy handmaid had two sons, and they two strove together in the field, and there was none to part them, but the one smote the other, and slew him."
Cross References (ranked by relevance)
Exodus 2:13
And when he went out the second day, behold, two men of the Hebrews strove together: and he said to him that did the wrong, Wherefore smitest thou thy fellow?
Genesis 4:8
And Cain talked with Abel his brother: and it came to pass, when they were in the field, that Cain rose up against Abel his brother, and slew him.