Mahabharata 3.220.1

मार्कण्डेय उवाच · mārkaṇḍeya uvāca

यदा स्कन्देन मातॄणामेवमेतत्प्रियं कृतम्अथैनमब्रवीत्स्वाहा मम पुत्रस्त्वमौरसः

yadā skandena mātṝṇāmevametatpriyaṃ kṛtamathainamabravītsvāhā mama putrastvamaurasaḥ

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