Charles Ellicott Commentary Psalms 143:10

"Teach me to do thy will; For thou art my God: Thy Spirit is good; Lead me in the land of uprightness." — Psalms 143:10 (ASV)

Your spirit is good; lead me. —Or, rather, let your good spirit lead me. (For the omission of the article with the adjective after the determinative noun, compare Genesis 37:2.)

Land of uprightness.— Better, level land (Deuteronomy 4:43, plain country), here metaphorically of tranquility and happiness. (Psalms 27:11.)