Isaiah 26:7 - Ellicott's Commentary On The Whole Bible

The way of the just is uprightness. — The English version seems somewhat tautologous. Better, is straight, or is even — i.e., leads on without interruption to its appointed end. So, in the second clause, instead of “thou shalt weigh the path,” which conveys a not very intelligible thought, we render, makest smooth the path. Probably, too, the word translated, “most upright,” as if it were a vocative, should be taken adverbially. The verse is, as it were, an echo of Proverbs 4:26; Proverbs 5:6; Proverbs 5:21.