The teachers of Brahman (Veda) declare, as the Prâtah-savana (morning-oblation) belongs to the Vasus, the Mâdhyandina-savana (noon-libation) to the Rudras, the third Savana (evening-libation) to the Âdityas and the Visve Devas,

In plain words: The teachers of the Vedas say that the morning offering belongs to the Vasus, the noon offering belongs to the Rudras, and the evening offering belongs to the Ādityas and the All-Gods. These are groups of gods.