Mahabharata 6.34.10

अभ्यासेऽप्यसमर्थोऽसि मत्कर्मपरमो भवमदर्थमपि कर्माणि कुर्वन्सिद्धिमवाप्स्यसि

abhyāse'pyasamartho'si matkarmaparamo bhavamadarthamapi karmāṇi kurvansiddhimavāpsyasi

Our plain-language meaning of this verse is waiting for scholar review.