Ramban on Exodus 24:6/רמב"ן על שמות כ״ד:ו׳

1AND MOSES TOOK HALF OF THE BLOOD AND HE PLACED IT ‘BA’AGANOTH.’ These are vessels made unlike the shape of the regular basins of the altar. Hence Scripture states that half of the blood of the sacrifices which Moses intended to sprinkle on the people, he put into these vessels, and the other half he sprinkled upon the altar from the regular basins in which he had received the blood, as is the customary way with all offerings. But Rabbi Abraham ibn Ezra said that ba’aganoth served for both halves, [and thus the word signifies the regular basins of the altar]. Such is also the opinion of Onkelos, who translated ba’aganoth as b’mizr’kaya [a term referring to the regular basins].