Mahabharata 13.74.26

गुरुशुश्रूषया शूराः पितृशुश्रूषयापरेमातृशुश्रूषया शूरा भैक्ष्यशूरास्तथापरे

guruśuśrūṣayā śūrāḥ pitṛśuśrūṣayāparemātṛśuśrūṣayā śūrā bhaikṣyaśūrāstathāpare

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