CHĀNDOGYA UPANISHAD · 1.12.1

अथातः शौव उद्गीथः ।
तद् ध बको दाल्भ्यो ग्लावो वा मैत्रेयः स्वाध्यायम् उद्वव्राज ॥

athātaḥ śauva udgīthaḥ ।
tad dha bako dālbhyo glāvo vā maitreyaḥ svādhyāyam udvavrāja ॥

Now follows the udgîtha of the dogs. Vaka Dâlbhya, or, as he was also called, Glâva Maitreya, went out to repeat the Veda (in a quiet place).