Mahabharata 12.313.15

तपसा गुरुवृत्त्या च ब्रह्मचर्येण चाभिभोदेवतानां पितॄणां चाप्यनृणश्चानसूयकः

tapasā guruvṛttyā ca brahmacaryeṇa cābhibhodevatānāṃ pitṝṇāṃ cāpyanṛṇaścānasūyakaḥ

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