- A Kohen with one foot on a כלי, etc., and one foot on the floor
The Mishnah on Daf 15b taught that if a Kohen performed קבלה while standing on a כלי, an animal, or someone’s feet, his avodah is invalid. A Baraisa derives this law by comparing the Mikdash floor, which is מקודשת – sanctified, and a כלי שרת, which is מקודש. Just as there can be no חציצה between the Kohen and the כלי שרת he uses for avodah, so too there cannot be a חציצה between the Kohen and the Mikdash floor during avodah. Rebbe Eliezer says: רגלו אחת על הכלי ורגלו אחת על הרצפה – If a Kohen stood with one of his feet on a utensil and one of his feet on the floor, or one foot on a stone (on top of the floor) and one foot on the floor, the rule is: כל שאילו ינטל הכלי ותנטל האבן – any case where, if the utensil or stone were removed, יכול לעמוד על רגלו אחת ויעבוד – he would be able to stand on his one foot which is on the floor and perform avodah, his avodah is valid. If he could not stand on that foot, his avodah is invalid.
- If a Kohen stood on a detached floor stone, or in its empty space
Rebbe Ami asked: נדלדלה האבן ועמד עליה – if a stone became loose and [a Kohen] stood on it, is his avodah valid? If he does not intend to reattach the stone, it is certainly a חציצה. The question is where he does intend to reattach it: do we say כיון דדעתו לחברה כמה דמחבר' דמיא – since he intends to attach it, it is considered already attached, so the Kohen is considered standing on the floor? Or, since it is currently detached, his avodah is invalid? A second version of this question is presented: נעקרה האבן ועמד במקומה – if a stone was removed from the floor and he stood in its place, is his avodah valid? Because Rebbe Ami did not ask about the entire עזרה floor, it is clear that he knew דעד ארעית דתהומא קדיש – that [Dovid] sanctified the ground until the earth of the deep, not just the surface. Rather, his question was: דרך שירות בכך – is this an appropriate manner of service to stand in a hole in the floor, or is this not דרך שירות? The Gemara concludes: תיקו – let [the question] stand unresolved.
- כל מקום שנאמר אצבע וכהונה אינה אלא ימין
Rabbah bar bar Chanah said in the name of Rebbe Yochanan: כל מקום שנאמר אצבע וכהונה אינה אלא ימין – wherever “a finger” and Kehunah are stated in a passuk, it means none other than the right hand. This is derived from מצורע, where the passuk uses both terms and explicitly requires ימין. Since the passuk of קמיצה only mentions Kehunah, and קמיצה with the left hand is פסול, Rava clarifies that wherever either "אצבע" or כהונה is written, it means to require ימין. Abaye asked Rava that regarding הולכת אברים לכבש – bringing the limbs [of a korban] to the ramp of the מזבח, the passuk mentions Kehunah, yet some limbs of the קרבן תמיד were carried in their left hands!? Rava answered that this rule only applies to something which is מעכב the כפרה, similar to the procedure of the מצורע. Regarding קבלה, where the passuk mentions כהונה, the Tanna Kamma of our Mishnah invalidates קבלה done with the left hand, but Rebbe Shimon validates it. The Gemara ultimately explains that Rebbe Shimon holds that "כהונה" does not require ימין; only "אצבע" does. Therefore, Rebbe Shimon also allows זריקה to be done with the left hand.