Which Parts of the Altar Are Indispensable

"And you shall put it under the ledge of the altar" (Exodus 27:5). Our Rabbis taught: The horn, the ramp, the base, and the square shape are indispensable; the measure of its length, the measure of its breadth, and the measure of its height are not indispensable. From where are these words derived? The verse says "the altar" [with the definite article], which comes only to render something indispensable. But if so, the basin according to Rabbi and the surrounding ledge according to Rabbi Yose bar Yehuda should likewise be indispensable, for it is written, "and you shall put it under the ledge of the altar," and it was taught: What is the ledge? Rabbi says: this is the basin; Rabbi Yose says: this is the surrounding ledge. Indeed, for it was taught: Any altar that has no horn, no ramp, no base, and no square shape is invalid. Rabbi Yose bar Yehuda says: also the surrounding ledge. Our Rabbis taught: What is the ledge? Between one horn and another. But is it not written, "under its ledge below, to its half" (Exodus 38:4)? Rav Nachman bar Yitzchak said: there were two places, one for beauty and one so that the priests should not slip. "The measure of its length and so forth are not indispensable." Rabbi Mani said: provided that it is not less than the altar of Moses. And how much was that? Rav Yosef said: the place of the arrangement, one cubit. What is the difference between a private altar and a communal altar? Leaning [of hands], slaughtering in the north, placing blood round about, waving, and bringing near. Rabbi Yehuda says: there is no meal-offering at a private altar, and the priesthood, the priestly garments, the service vessels, the pleasing aroma, the partition for the blood, and the washing of hands and feet. But the matter of time, of leftover sacrifice, and of impurity are equal in both. Leaning, as it is written, "before the LORD, and he shall lean" (Leviticus 3:8). Slaughtering in the north, as it is written, "on the side of the altar northward" (Leviticus 1:11). Placing blood round about, as it is written, "and the sons of Aaron the priests shall throw" and so forth (Leviticus 1:5). Waving, as it is written, "and Aaron waved" (Leviticus 9:21). Bringing near, as it is written, "and he shall bring it near to the altar" (Leviticus 2:8). "Rabbi Yehuda says: there is no meal-offering and so forth." Rav Sheshet said: According to the one who says there is a meal-offering at a private altar, there are bird-offerings at a private altar; according to the one who says there is no meal-offering, there are no bird-offerings. What is the reason? "Animal-sacrifices" and not birds, "animal-sacrifices" and not meal-offerings. The priesthood, as it is written, "and the priest shall throw" (Leviticus 17:6). The service garments, as it is written, "to minister in the holy place" (Exodus 28:43). The pleasing aroma, as it is written, "a pleasing aroma to the LORD." The partition for the blood, as it is written, "and the net shall reach to the half of the altar." And that hands and feet need not be washed, as it is written, "when they come into the tent of meeting they shall wash with water" (Exodus 30:20).