Gemara

47b (Abaye): If one wove a garment for a Mes, one may not benefit from it;

(Rava): One may benefit from it.

Abaye forbids, because Hazmanah (designation) takes effect. Rava permits, for Hazmanah has no effect.

(Rav Chisda): If a cloth was designated and used to wrap Tefilin, one may not wrap coins in it. If it was designated but not yet used to wrap Tefilin, or used but not designated, one may wrap coins in it.

Abaye holds that it depends only on Hazmanah. If it was designated, even if it was not yet used for Tefilin, one may not wrap coins in it. If it was not designated, even if it was used for Tefilin, one may wrap coins in it.

48b - Question (against Rava): If a bag was made to hold Tefilin, one may not put coins in it. If it was not made for Tefilin but Tefilin were put in it, one may put coins in it.

Answer: The Reisha should say 'if it was made for Tefilin and Tefilin were put in, one may not put coins in it (like Rav Chisda's teaching above).

Question (against Abaye - Beraisa): If Reuven told a craftsman 'make me a cover for a Sefer Torah (or for Tefilin)', he may use it for Chulin only until he uses it for Kodesh. Afterwards, it is forbidden.

Answer: Tana'im argue about Hazmanah.

(Beraisa): If (the Batim of) Tefilin were covered with hide of a Tahor animal, they are Kosher, even if the hide was not tanned for Tefilin;

R. Shimon ben Gamliel says, if the hide was not tanned Lishmah (for the sake of Tefilin), they are Pasul.

The Halachah follows Rava.

Rishonim

Rif and Rosh (6:4): The Halachah follows Rava. If a cloth was designated and used to wrap Tefilin, one may not wrap coins in it. If it was designated but not yet used to wrap Tefilin, or used but not designated, one may wrap coins in it.

Nimukei Yosef (DH Sudrei): Rav Acha says that this is not only if he wrapped Tefilin in it with intent to do so permanently. If so, obviously it is forbidden! Also, if so, we could not say that if it was used but not designated, one may wrap coins in it. Putting Tefilin in it is full Hazmanah and action, and it becomes Kodesh! This does not depend on the argument of Abaye and Rava. Rather, even if he temporarily wrapped Tefilin in it, if he designated it from the beginning, Rava admits that it is forbidden. It seems that Rashi agrees, for he said that if he wrapped Tefilin in it but did not designate it, since he did so temporarily, it is permitted. This is after removing the Tefilin. While the Tefilin are inside, it is forbidden. Even though he** said in the name of his Rebbi that even if he wrapped Tefilin in it with intent to do so permanently, if he had not designated it from the beginning it is permitted. He** also wrote that here we discuss Hazmanah of Tashmishim (what serves the matter), but Hazmanah of the matter itself helps, e.g. tanning hide for Tefilin boxes or parchments. If one did so Lishmah, this Hazmanah alone forbids using them for Chulin.

(Note: I suspect that 'he' refers to the Ritva, whom the Nimukei Yosef often cites, who often says mi'Pi Mori ha'Rav Nero'. Perhaps this entire Nimukei Yosef is from the Ritva.)

Ba'al ha'Ma'or (Sukah 4b): The argument is only about Tashmishei (things used for a Mitzvah) or Tashmishei Kedushah, e.g. a garment woven for a Mes or Tzitzis from balls of thread and Tefilin straps, but all agree that the writing itself of Tefilin or a Sefer Torah requires Lishmah.

Magen Avraham (43:6): We discuss Divrei Kedushah such as Tefilin. Tashmishei Mitzvah, e.g. Tzitzis, Shofar, Lulav or Ner Chanukah, even if they were made for this, may be used for Chulin. The Ba'al ha'Ma'or connotes like this.

Rosh (Megilah 4:11): The Yerushalmi permits a cabinet with different parts. A Sefer Torah was put in one part. They were permitted to put Kelim in another part, for they stipulated from the beginning.

Poskim

Shulchan Aruch (42:3): If a cloth was permanently designated to wrap Tefilin, and one wrapped Tefilin in it once, one may not wrap coins in it.

Beis Yosef (DH Sudar): The Mordechai (Megilah 819) says that Hazmanah is permanent, not temporary. Then we say that if he wrapped in it once, it became Kodesh. This connotes that if he wrapped in it once with intent to wrap in it permanently, this is Hazmanah and wrapping in it. It seems that the Ramban (Toras ha'Adam, regarding a grave) agrees.

Gra (4): Rashi (Avodah Zarah 47b DH Hichnis) says that if idolatry was temporarily brought into a house, the house is permitted after it is removed.

Magen Avraham (4): If a minor wrapped Tefilin in it, it is forbidden. However, a minor's Hazmanah does not forbid something that is forbidden through Hazmanah alone, for we say that a minor's act takes effect, but his intent does not (Chulin 13a). Clearly, one may not forbid what is not his (YD Sof Siman 349). If one stole a bag and wrapped Tefilin in it, he acquired through Shinuy Ma'aseh, and forbade it.

Magen Avraham (5): If one made a bag for the sake of Tefilin, even if he wrapped in it once with intent to remove it, it is forbidden. The same applies if he had a bag and added something for the sake of Tefilin and wrapped in it once with intent to remove it, it is forbidden until he removes the addition.

Mishnah Berurah (9): The same applies to all Tashmishei Kedushah, even a case for a Sefer Torah. Tashmishim of Tashmishim have no Kedushah.

Mishnah Berurah (10): Hazmanah is through mere speech, and all the more so if he picked it up and said 'this will be for Tefilin.'

Mishnah Berurah (11): A Talis bag is not Tashmishei Kedushah, rather, Tashmishei Mitzvah, so one may put Chulin in it, even while the Tefilin bag is inside. The Talis bag it is only Tashmish d'Tashmish. Even if one put his Sidur inside, which is Kedushah, or his Tefilin without a bag, when needed he may put Chulin inside, for initially it was made also for the Talis, which is Chulin. It is as if he stipulated.

Mishnah Berurah (12): Some say that he must specify that he designates permanently, but Stam Hazmanah is temporary, since a Stam cloth is not for Tefilin. However, the Gra connotes that Stam Hazmanah is permanent, unless he specified that it is temporary. If one made a bag for Tefilin, or told a craftsman to make one, all agree that Stam is permanent.

Mishnah Berurah (14): Even if he used the cloth temporarily, it joins with the Hazmanah to forbid. If he specified when putting the Tefilin in that it is with intent to remove them later, one may use it for Chulin later, unless the bag was made for Tefilin or something was added for Tefilin.

Mishnah Berurah (15): One may not put in it anything with less Kedushah than Tefilin, e.g. a Mezuzah or Sidur. However, one need not protest against one who does. Since people often do, it is as if they stipulated from the beginning.

Rema: If he stipulated from the beginning, it is permitted in every case.

Taz (1): This implies that an explicit stipulation is needed. Many people, when going on a trip, put things that hey will need in the Tefilin bag. This is improper. We can offer some defense, and say that for such people, Stam is as if they explicitly stipulated. The Rema (154:8) says that the custom is to get several benefits from Divrei Kedushah. Since it is the custom and people cannot be careful about this, Beis Din stipulates about this from the beginning. Likewise, one who buys a Tefilin bag intends to use it like people do when traveling.

Magen Avraham (6): A stipulation permits to use for Chulin even for Divrei Kedushah. Some permit even without a stipulation. A Get is not Divrei Kedushah. However, once one started writing Divrei Kedushah on a parchment or paper, he may not write Chulin on it. A Tanai helps for Tashmishei Kedushah, even while they have Kedushah, but not for disgraceful uses.

Shulchan Aruch (ibid): If it was designated but not yet used to wrap Tefilin, or used but not designated, one may wrap coins in it.

Mishnah Berurah (24): This is if he wrapped in it temporarily, even several times, but did not permanently designate it and never intended to use it permanently.

Mishnah Berurah (26): Some say that when the Tefilin are inside it is not honorable to put money in at the same time. Rather, the money should be tied in a separate bundle.