Chandogya Upanishad 2.69

पुरा प्रातरनुवाकस्योपाकरणाज्जघनेन गार्हपत्यस्योदाङ्मुख उपविश्य स वासवꣳसामाभिगायति ॥ ३ ॥

2.24.3 — pura prataranuvakasyopakaranajjaghanena garhapatyasyodanmukha upavishya sa vasavamsamabhigayati || 3 ||

Before the beginning of the Prâtaranuvâka (matin-chant), the sacrificer, sitting down behind the household altar (gârhapatya), and looking towards the north, sings the Sâman, addressed to the Vasus:

प्रातरनुवाक के उपाकरण (आरम्भ-विधि) से पूर्व, गार्हपत्य के पिछले भाग में उत्तराभिमुख बैठकर, वह यजमान वसु-सम्बन्धी साम का गान करता है —