Reference for Yoma 4:6
בְּכָל יוֹם הָיוּ שָׁם אַרְבַּע מַעֲרָכוֹת, וְהַיּוֹם חָמֵשׁ, דִּבְרֵי רַבִּי מֵאִיר. רַבִּי יוֹסֵי אוֹמֵר, בְּכָל יוֹם שָׁלשׁ, וְהַיּוֹם אַרְבַּע. רַבִּי יְהוּדָה אוֹמֵר, בְּכָל יוֹם שְׁתַּיִם, וְהַיּוֹם שָׁלשׁ:
Every day there were four wood piles there [on the outer altar. There were four wood piles on which fire was kindled: one, the large wood pile on which the tamid was sacrificed; another, the second wood pile from which fire was taken for the altar of the incense; a third, the wood pile of the perpetuation of the fire, that fire never fail from the altar; and the fourth, the wood pile of the limbs and the fat-pieces of the afternoon tamid, which (limbs) had not been consumed from the evening and which had not been burned the entire night. They are burned in this wood pile. And on Yom Kippur another wood pile is added from which are taken the coals for the incense (offering) in the holy of holies.] These are the words of R. Meir. R. Yossi says: Every day, three; and today, four. [For there are three verses in this regard: (Leviticus 6:2): "…upon its fire-wood on the altar all the night until the morning." This is the large wood-pile. (Ibid. 5): "And fire of the altar shall be kindled thereby." This is the second wood pile, of the incense. (Ibid. 5): "And the fire upon the altar shall burn thereby; it shall not be extinguished." This is the third wood pile, of the perpetuation of the fire. And R. Yossi does not hold that there is a fourth wood pile for unconsumed limbs and fat-pieces, holding that these are burned at the sides of the large wood pile.] R. Yehudah says: Every day, four; and today, three, [R. Yehudah not holding that there is a third wood pile for the perpetuation of the fire. As to: "And the fire upon the altar shall burn thereby; it shall not be extinguished," he expounds that as meaning that one who lights small pieces of wood with which to kindle the large wood pile should not light them on the floor and bring them up to the altar, but should light them on the top of the altar. The halachah is in accordance with R. Yossi.]