Arabic expressionMeaning / grammar cue
لَيْسَ الشَّدِيدُ بِالصُّرَعَةِNegates an incomplete definition of strength; بِـ occurs in the predicate
لَيْسَ مِنَّاA strong moral warning: “not following our way”
لَيْسَ الْغِنَى عَنْ كَثْرَةِ الْعَرَضِRejects a limited measure of wealth
لَيْسَ الْخَبَرُ كَالْمُعَايَنَةِNegates equivalence between a report and direct sight
لَيْسَ typically negates a nominal relationship between a subject and predicate; بِـ may emphasize negation in its predicate. The full wording and context—not a single isolated term—determine the intended meaning.