2245 —סדר בתפילין ובמזוזות, המונח "שבת ברכות", וברכה

[5713] ...a) Regarding your doubt about the Rambam's opinion on the law of writing Tefillin and Mezuzos out of order—it is clear that he invalidates them, as written in Hilchos Tefillin 1:16. See there in the commentaries on Rambam, Tzafnas Paneach there, Ba'er HaGolah to Shulchan Aruch Yoreh Deah 32:23, and others. Your attempt in your letter to explain the Rambam's reasoning there was unnecessary.

b) It is obvious that the Rambam brings in his Mishneh Torah laws from the Yerushalmi, Mechilta, etc., even if they are not mentioned in the Bavli, as long as the Bavli does not disagree.

c) For the source of invalidation for writing out of order in Tefillin and Mezuzos—see also Shu"t tzt"z Shaar HaMiluyim section 3.

d) Whether this invalidation is from Torah law or rabbinic—see Shu"t Radbaz vol. 1 siman 310; Mishbetzos Zahav at beginning of Siman 32 and beginning of Siman 34; tzt"z and Tzafnas Paneach there; Keset HaSofer section 9; Ot Chaim (by author of Menachem Aharon) at beginning of Siman 32; and books cited in Sefer Maasef Lechol HaMachanos there.

e) The name "Shabbos Berachos"—after publishing Kuntres HaAvodah I learned that this is how it is called in many places in Poland, etc. And finally, a beloved blessing: at any time is its proper time—may it be G‑d's will that he and his wife raise their son Mordechai together with their other children for Torah, marriage, and good deeds with proper health and true abundance.

The name "Shabbos Berachos": see also above Vol. III Igros number 931 section 7. Kuntres HaAvodah: p.6 note by our Rebbe shlita there "requires further clarification regarding this word." And see what Y. Mundshine wrote about this in Kovetz He'aros U'Biurim issue 339 p.7.

Summary

This letter addresses halachic details regarding Tefillin and Mezuzos, explores traditional terminology like "Shabbos Berachos," and ends with a warm blessing for raising children with health, Torah values, and success.