Chandogya Upanishad 8.11.3

8.11.3

evam evaiṣa maghavann iti hovāca \
etaṃ tv eva te bhūyo 'nuvyākhyāsyāmi \
no evānyatraitasmāt \
vasāparāṇi pañca varṣāṇīti \
sa hāparāṇi pañca varṣāṇyuvāsa \
tāny ekaśataṃ saṃpeduḥ \
etat tad yad āhuḥ \
ekaśataṃ ha vai varṣāṇi maghavān prajāpatau brahmacaryam uvāsa \
tasmai hovāca \\811.3\

‘So is it, indeed, O Indra’, said Prajāpati; ‘however, I shall explain this further to you and none other than this. Live here for another five years’. He lived there for another five years. That makes one hundred and one years and so with regard to that, people say thus, ‘Verily, for one hundred and one years Indra lived with Prajāpati the disciplined life of a celibate student of sacred knowledge.’ Then Prajāpati said to him :