Psalm 18:26 in the World English Bible
With the pure, you will show yourself pure. With the crooked you will show yourself shrewd.
Context
25 With the merciful thou wilt shew thyself merciful; with an upright man thou wilt shew thyself upright;
26 With the pure thou wilt shew thyself pure; and with the froward thou wilt shew thyself froward.
27 For thou wilt save the afflicted people; but wilt bring down high looks.