One of the central parts of the special service performed by the kohen gadol on Yom Kippur, involved his entering the kodesh kodashim and sprinkling the blood from his sacrifices towards the Holy Ark that stood there. According to the Gemara in Massekhet Yoma, the passage that serves as the source for this (see Vayikra 16:14) is understood by the Sages to require the kohen gadol to sprinkle one time upwards and seven times downwards.
The Gemara on today’s daf refers to the Mishna in Yoma where this halakha appears, together with the explanation that appears in the Mishna, that the kohen gadol did not intend to actually sprinkle upwards or downwards, rather he did it ke-matzlif. Rav Yehuda indicated that this term means “like someone who is giving lashes.”
According to Rashi, Rav Yehuda’s explanation should be understood to mean that the sprinkling took place on two separate parts of the ark, on the top of the cover of the ark and on its side. Rabbeinu Ḥananel suggests that the intention of the Gemara is that someone who gives lashes raises and lowers his hand while doing so, but hits the same spot repeatedly. The Gemara in Yoma explains that the Mishna refers to how the kohen gadol‘s hand was positioned – was it facing upwards or downwards? The single “upwards” sprinkling required the kohen gadol to hold his hand with his palm facing downwards, so that the blood would be sprinkled upwards. The seven “downwards” sprinklings required him to turn his hand upwards so that the blood would be sprinkled downwards. Some explain the comparison to giving lashes based on the requirement that the person receiving the lashes be beaten on the front of his body as well as the back (see Massekhet Makkot 22b). Since that person was in a bent over position when he received the lashes, the person giving the lashes had to turn his hand upwards in order to fulfill the requirement.