Why does the Torah write "v'Im," implying that building a stone Mizbe'ach is voluntary?
Rashi (citing the Mechilta): This is one of three occasions where the Torah uses the word "Im" even though the issue is obligatory, 1 in place of 'Ka'asher' (when). 2
Ramban #1, Targum Onkelos and Targum Yonasan: The Torah is saying that, if (when) the time arrives that Yisrael merit inheriting the land and building a stone Mizbe'ach in the Beis ha'Mikdash, they should take care that the stones should not be hewn.
Ramban #2 (citing Ibn Ezra): It is said with reference to Mizbe'ach ha'Bris that Moshe built at the foot of Har Sinai. 3
See Ki Savo, Devarim 27:6.
Rashi: The other two are a. "Im Kesef Talveh" - Shemos 22:24 (See Devarim 15:8) and b. "v'Im Takriv Minchas Bikurim" regarding Minchas ha'Omer, Vayikra 2:14 (See Vayikra 23:9). Moshav Zekenim - he did not include "Im Kofer Yushas Alav," for it is only if a Mu'ad ox kills a person; it is not always a Chiyuv. Moshav Zekenim (21:30, citing R. Yeshayah) - it is not a Mitzvah. Bartenura - "v'Im Yihyeh ha'Yovel" does not teach the Mitzvah of Yovel. It merely teaches about the inheritance of Benos Tzlafchad.
As described in Shemos 24:4.
If building a Mizbe'ach of stones is obligatory, why does the Torah write "v'Im Mizbach Avanim ... '?
Mechilta: To teach us that one has the option of building it of bricks.
Oznayim la'Torah: Because this Pasuk is referring to after they cross the Yarden, when it will become possible to build a Mizbe'ach of stones, 1 and "Im" means 'when.'
As the Pasuk specifically states in Parshas Ki Savo (Devarim 27:2). See Oznayim la'Torah.
What is the significance of the fact that the Torah mentions "Avanim" three times in connection with Mizbe'ach - once here and twice in Parshas Ki Savo (Devarim 27:2,7?
Zevachim 61b: It is a hint at the three future stone Mizb'chos that would be built - one in Shiloh, one in Nov and in Giv'on 1 and one in the Beis-Hamikdash.
Which are counted as one. See also Torah Temimah, note 126.
What is the definition of "Gazis"?
Mechilta: 'Hewn by an iron implement.' 1
But one that is hewn by a copper or silver implement is permitted. See Torah Temimah, note 131.
What are the implications of the word "Lo Sivneh Es'hen Gazis"?
Mechilta #1: It implies that only the Mizbe'ach may not be built of hewn stones, but that one may use hewn stones in the Kodesh and in the Kodesh Kodashim. 1
Mechilta #2: It implies that the stones that are hewn are Pasul 2 but the rest of the Mizbe'ach is Kasher.
Why will using a sword on the stones of the Mizbe'ach disqualify it?
Rashi #1, Ramban (citing the Mechilta) and Targum Yonasan: Because, since the purpose of the Mizbe'ach is to prolong life, whereas iron (from which a sword is made - Targum Yonasan) 1 curtails life, it would not be correct to use the latter in manufacturing the former.
Rashi #2, Ramban #4: The Mizbe'ach creates peace between Yisrael and their Father in Heaven, it would not be correct a sword that causes destruction 2 to manufacture it. 3 (Moreover, Eisav, whom Hashem hates 4 inherited the sword 5 - it portrays his strength both on earth and in Heaven; 6 therefore it is not befitting to use a sword (iron) in the Beis-Hamikdash - Ramban). 7
Ramban #2 (citing the Ibn Ezra): It is to prevent a scenario where the chippings end up in the trash-heap, or where the adherents of Avodah-Zarah take some of the chippings to make a Mizbe'ach for Avodah-Zarah. 8
Ramban #3 (citing the Moreh Nevuchim, 3:45) and Rashbam: It is a decree to prevent them from carving pictures on the Mizbe'ach. 9
Ramban (DH v'Zehu ha'Ta'am): However, one may use other metals or the Shamir worm to cut or form the stones of the Mizbe'ach - even though this renders the stones incomplete,
Ramban: Which is why a sword is called "Cherev."
Rashi (citing the Mechilta): And if the Torah says this in connection with the stones of the Mizbe'ach, which cannot hear, see or speak, how much more so will no harm befall someone who makes peace between man and wife, family and family and between one man and another.
Ramban: As the Pasuk states in Mal'achi 1:3.
See Bereishis 27:40.
In the form of Mazal Ma'adim, the Mazal that depicts bloodshed.
Ramban: With the exception of the Shechitah-knives, which were permitted because Shechitah is not an Avodah.
Ibn Ezra:Whose adherents would do so in anticipation of success in their endeavors (bearing in mind the strong Yetzer-ha'Ra for Avodah-Zarah, until Ezra and his Beis-Din negated it).
Thereby turning it into 'Even Maskis,' which the Torah forbids in the Beis-Hamikdash. See Vayikra 26:1 (Moreh Nevuchim). According to the Rashbam it is an extension of the prohibition in Pasuk 20 (Refer to 20:21:1:6).
