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

Genesis 4:8 records Cain killing Abel in a field — the woman's story of two sons fighting in a field echoes this first fratricide.

Deuteronomy 22:26 uses the same legal analogy of a man killing his neighbor in the field, paralleling the scenario of the woman's sons.