CHĀNDOGYA UPANISHAD · 1.3.8

अथ खल्व् आशीः समृद्धिः ।
उपसरणानीत्य् उपासीत ।
येन साम्ना स्तोष्यन् स्यात् तत् सामोपधावेत् ॥

atha khalv āśīḥ samṛddhiḥ ।
upasaraṇānīty upāsīta ।
yena sāmnā stoṣyan syāt tat sāmopadhāvet ॥

Next follows the fulfilment of prayers. Let a man thus meditate on the Upasaranas, i. e. the objects which have to be approached by meditation: Let him (the Udgâtri) quickly reflect on the Sâman with which he is going to praise;