Charak Samhita
सशास्त्रमन्यदप्याशुयुक्तिज्ञत्वात्प्रबुध्यते। अधीयानोऽपिशास्त्राणितन्त्रयुक्त्याविनाभिषक्। नाधिगच्छतिशास्त्रार्थानर्थान्भाग्यक्षयेयथा॥४८॥
But one who is not conversant with tantrayuktis can not understand his own texts as well the others too at any cost, same as a person fails to get wealth in spite of all efforts when his fortune does not favors him.
english translation
sazAstramanyadapyAzuyuktijJatvAtprabudhyate। adhIyAno'pizAstrANitantrayuktyAvinAbhiSak। nAdhigacchatizAstrArthAnarthAnbhAgyakSayeyathA॥48॥
hk transliteration by Sanscript