What are the implications of the word "u'Chesavtam"?
B'rachos, 15b: It implies that one should write the entire Parhah 1 in the Tefilin - even the commands ("Ve'ahavta ... ", "Vehayu ha'Devarim ha'Eileh ... ", "u'Keshartam ... " and u'Chesavtam ... ". 2
Shabbos, 103b: It implies 'Kesivah Tamah' (See answer #1 and note) - that one should not write an 'Alef' like an 'Ayin', 3 a 'Beis' like a 'Kaf' or a 'Daled' like a 'Reish', or vice-versa. 4 And by the same token, one should also take care not to switch an open 'Mem' for a closed one, or vice-versa.
Menachos, 34a: It implies 'Kesivah Tamah' (See answer #1 and note) - that one should not write the Mezuzah on (the) stones (of the doorpost - but on parchment - Torah Temimah). 5
"u'Chesavtam" is the acronym of 'Kesivah Tamah'.
And not just "Sh'ma Yisrael" - Kabalas Ol Malchus Shamayim.
Torah Temimah: Which are often confused beause they sound similar.
Which look similar. See also Torah Temimah, citing Shabbos, Ibid. for more examples and note 49.
Menachos (Ibid.): Others learnit from aa Gezeirah Shavah 'Kesivsh' 'Kesivah' from Get - ki Seitzei,24:1 & 3.
Why is "Mezuzos" written Chaser (minus a 'Vav')?
Rashi: "Mezuzos" is written Chaser (minus a 'Vav') to teach us that each doorway requires only one Mezuzah 1 - since the word can be read 'Mezuzas'.
Whereabouts on the doorpost does one fix the Mezuzah?
Why is "Mezuzos" written in the plural?
Menachos, 34a (according to the Chachamim): To teach us that a doorway with only one doorpost is Patur from Mezuzah. 1
See Torah Temimah, note 54. See also Torah Temimah, citing Menachos, Ibid., citing R. Meir - that, since the Torah writes twice "Mezuzos" (plural) - once here and once in 'Eikev', 11:20, and since a Ribuy after a Ribuy comes to exclude, even one doorpost is also Chayav Mezuzah. See Torah Temimah, who elaborates.
What are the implications of the word "Beisecha"?
Rashi (in Bava Metzi'a, 101a): "Beisecha"
Menachos, 34a: "Beisecha" implies 'Derech Bi'ascha' - and one generally begins walking with the right foot. See Torah Temimah, note 62, who discusses a house belonging to a person who is left-handed.
See Torah Temimah, note 57.
See Torah Temimah, note 60, who discusses a Shul.
See Torah Temimah, note 61.
Why does the Torah add the suffix "Beisecha"?
Yoma, 11a: To preclude from Mezuzah a store-house of straw or wood, a stable and a store for wine or oil - all of which are not for personal living. 1
Tosfos Avodah Zarah, 21a: To preclude a rented room from Mezuzah. 2
What are the implications of the word "u'vi'Sh'arecha"?
Why does the Torah add the 'Veis' in Beisecha u'vi'She'arecha"?
Oznayim la'Torah (citing the Ha'amek Davar): To teach us that in locations which are not guarded and are not clean - such as those on the gate of courtyards and towns, should be placed inside a crevice in the wall. 1
Oznayim la'Torah (Ibid.): As opposed to those that are placed on houses, should preferebly be placed on the outside of the wall, where they are visible.
QUESTIONS ON RASHI
Rashi writes that "Mezuzos" is written without the second 'Vav'. But in our texts it is written 'full'?
Riva (in Chayei Sarah, 25:6): We find that the Gemara 1 disagrees with our tradition (in several places).
Tosfos (Menachos 34a DH ke'she'Hu): R. Meir learns from Ribuy after Ribuy - Refer to 6:9:2.1:1* - implying that it is written full.