QUESTION: Rava says that mid'Oraisa, the Korban Tamid may be brought from
the time that the sun begins to turn towards the west. In explaining what
hour this refers to, RASHI (DH Ela Amar Rava) first writes that the Tamid
may be brought during "the last six hours of the day." However, Rashi then
writes that the time for bringing the Tamid is from six and a half hours
onward, when the shadows lean towards the east and are not directly under
the person (in other words, the last five and a half hours of the day).
Rashi is clearly contradicting himself!
The GILYON HA'SHAS points out that later in the Gemara (93b) Rashi writes
explicitly that the time of the Korban Tamid is from exactly Chatzos
(midday) and onward. Rashi there says that the source for this is from the
Gemara in Yoma (28b) which states that if not for the fact that the walls of
the Azarah were sloped, the Korban would have been brought earlier, but
since the walls are sloped and it is not possible to see their shadows until
a half hour after midday (six and a half hours into the day), therefore the
Korban is brought only from that time and on.
ANSWER: The TZELACH answers that perhaps Rashi's intention is to explain our
Gemara in accordance with the Gemara in Yoma, which Rashi quotes later (and
which Tosfos also quotes here, DH Mukminan). Thus, Rashi means to say that
mid'Oraisa, the Korban Tamid may be brought from six hours and on. When
Rashi says here that the time to bring the Tamid is from "six and a half
hours," he means to say because one must wait for the shade to appear, the
Rabanan therefore said that one has to wait until six and a half hours, and
for this reason the Mishnah says six and a half hours.
What does Rashi mean when he says that a person's shadow does not appear
until six and a half hours? The Gemara in Yoma says that there is shade at
*six* hours, and it is only the sloped walls that do not have shadows until
six and a half!
It could be that Rashi holds that a person is like a sloped wall, since he
is narrow on top and broad on bottom, and thus when using the shade of a
person as a sign for midday, one does not see his shadow until six and a
half hours. Only a straight wall has shade beneath it at exactly six hours.