1 Samuel 24:13

As saith the proverb of the ancients, Wickedness proceedeth from the wicked: but mine hand shall not be upon thee.

The setting places a shepherd boy who carried God's promise of the throne over against an established king resolved to cling to his power. The one held nothing but the divine word, while the other commanded the standing authority of the kingdom and sought to keep it by force. Though entirely helpless in himself, the younger man stood firm against the king and against the strength of the whole world arrayed with him. His ability to withstand came not from arms or followers but from trusting what God had spoken.

The old saying quoted at that moment means that evil deeds spring from evil persons. By refusing to lift his hand against his pursuer, David proved that no such evil purpose was in him toward the king.