Deuteronomy 9:4-5

Speak not thou in thine heart (cf. Deuteronomy 8:17 ). The distinction between righteousness and uprightness (straightness) of heart, is that the former ( צֶדֶך ) has reference to rectitude of conduct, the latter ( ישֶׁר ) to rectitude of motive and purpose. "By naming justice [righteousness], he excludeth all merit of works, and by righteousness [uprightness] of heart, all inward affections and purposes. which men might plead, notwithstanding that they fail in action. Yet these two are the chief things which God respecteth in men ( Psalms 15:1 , Psalms 15:2 ; 1 Chronicles 29:17 )" (Ainsworth).