पुरा तृतीयसवनस्योपाकरणाज्जघनेनाहवनीयस्योदङ्मुख उपविश्य स आदित्यंस वैश्वदेवं सामाभिगायति ॥ २.२४.११ ॥
In plain words
Before the beginning of the third pressing, let him sit down behind the offering fire facing north and sing the Sāman of the Ādityas and the Sāman of the All-gods: