Rahab lied to her king about where the spies were. In order to save their lives.

(Joshua 2:2-6 NIV) The king of Jericho was told, "Look! Some of the Israelites have come here tonight to spy out the land." {3} So the king of Jericho sent this message to Rahab: "Bring out the men who came to you and entered your house, because they have come to spy out the whole land." {4} But the woman had taken the two men and hidden them. She said, "Yes, the men came to me, but I did not know where they had come from. {5} At dusk, when it was time to close the city gate, the men left. I don't know which way they went. Go after them quickly. You may catch up with them." {6} (But she had taken them up to the roof and hidden them under the stalks of flax she had laid out on the roof.)

(Hebrews 11:31 NIV) By faith the prostitute Rahab, because she welcomed the spies, was not killed with those who were disobedient.

(James 2:25 NIV) In the same way, was not even Rahab the prostitute considered righteous for what she did when she gave lodging to the spies and sent them off in a different direction?