Gemara

Beraisa: After three Regalim one is liable if he did not fulfill any of the following obligations:

...Hekdeshos, Chata'os,... Tzedakos, Ma'aseros, Leket, Shichchah and Pe'ah...

6a: "B'Ficha" teaches that Bal Te'acher applies to Tzedakah.

Rava: One is liable immediately for delaying to give Tzedakah.

Question: What is the reason?

Answer: There are Aniyim here (he need not go to Yerushalayim to fulfill it).

Objection: This is obvious!

Answer: One might have thought that since it is written amidst Korbanos, one is not liable until three Regalim, like Korbanos. Rava teaches that this is not so;

The Torah says that Korbanos depend on Regalim, but not Tzedakah, because there are Aniyim here.

Rishonim

Rif: One is liable immediately for Tzedakah, because there are Aniyim here.

Question: A Beraisa says that the Shi'ur for Charamos, Tzedakah, Ma'aseros... is three Regalim!

Answer #1 (Tosfos 4a DH Tzedakos): This is when Aniyim are not here. After three Regalim, one must pursue them.

Objection (Rashba DH Tzedakos): If so, we should similarly distinguish regarding Korbanos, and say that one transgresses immediately if there are Kohanim in the Mikdash!

Answer #2 (Rashba ibid.): One transgresses an Aseh immediately for Tzedakah. He does not transgress the Lav until three Regalim.

Objection (Tosfos ibid.): If Rava teaches about transgressing an Aseh, this should be after one Regel, like Korbanos!

Answer #3 (Ran DH u'Tzedakah): The Shi'ur of three Regalim applies only to things that depend on the Mikdash. One transgresses Tzedakah immediately. The Torah does not distinguish whether or not Aniyim are around, or whether or not there are Kohanim in the Mikdash. The Beraisa teaches that Bal Te'acher applies to all the matters listed, within three Regalim. It does not say that one does not transgress any of them before this. Since one could err, Rava explained that one transgresses Tzedakah immediately.

Gra (YD 257:6): The Shi'ur of three Regalim applies only to matters of the Mikdash. Since one must go there for Aliyah l'Regel in any case, he should fulfill his obligations at that time.

Ran (DH v'Nimtzeis): The Gemara said that Bal Te'acher applies even if he did not separate the Korban yet. Similarly, regarding Tzedakah one must separate the money even if there are not Aniyim here. However, he need not pursue them to give it to them.

Question: When people vow Tzedakah in the Beis ha'Keneses or at home, do they transgress Bal Te'acher immediately when Aniyim are around?

Answer (Ran DH v'Chosvu, citing R. Tam): If Reuven vowed and gave the money to the Gabai he is exempt, for there is nothing else for Reuven to do. The Gabai does not transgress if he waits for proper Aniyim, or if he distributes it bit by bit. One vows on condition that he will be the Gabai, to give it like he sees fit. R. Tam must explain that Rava requires one who vowed Tzedakah to plan to distribute it immediately. If he decides to delay (even if he will find proper recipients), he transgresses.

Rambam (Hilchos Matanos Aniyim 8:1): Tzedakah is a Neder. Therefore, if one said 'Alai (it is incumbent on me) to give a Sela to Tzedakah' or 'this Sela is for Tzedakah', he must give to Aniyim immediately. If he delays he transgresses Bal Te'acher, because he could give and Aniyim are found. If there are not Aniyim, he separates the money and leaves it until he finds Aniyim. If he stipulates not to give until he finds an Oni, he need not separate. Similarly, if he stipulated at the time that the Gabai'im may change it or convert it to gold, this is permitted.

Question (Tur YD 257): The Rambam permits stipulating only when there are not Aniyim. This is wrong. Also, when there are not Aniyim there is no need to stipulate!

Answer #1 (Beis Yosef DH u'Mah she'Chosav Alav and DH u'Mah she'Chosav Od): Perhaps the Rambam permits stipulating even when there are Aniyim; he merely discusses a typical case. The stipulation exempts him from the need to separate the money.

Answer #2 (Bach DH u'Mah she'Chosav b'Shem): A stipulation does not help when Aniyim are found, just like it does not help for Korbanos after three Regalim.

Answer #3 (Aruch ha'Shulchan 4): Even for Korbanos, one may stipulate from the beginning that he will bring it after several years! Rather, the Rambam teaches that even if one stipulated not to give until he finds an Oni, his intent was not to give to the Gabai until there are Aniyim, hence he need not even separate now. Also, he teaches that the stipulation of the Noder helps for the Gabai.

Rambam (Hilchos Pesulei ha'Mukdashim 14:13): It is a Mitzvas Aseh to fulfill Nedarim, Nedavos and other obligations to pay Erchin, Damim, Ma'aseros and Matanos Aniyim at the first Regel. If he did not bring them at the Regel, he was Mevatel the Aseh. If he did not bring Korbanos, Erchin, Charamos or Damim within three Regalim he transgresses "Lo Se'acher Leshalmo".

Ri Korkus: The Rambam holds like the Ran, that Rava teaches that Bal Te'acher applies to Tzedakah. He did not mean that the time (number of Regalim) after which one transgresses is the same. This is why he did not mention Tzedakah here. He does say that Matanos Aniyim depend on Regalim. Perhaps Tzedakah is different. Since it comes through a Neder, one is obligated immediately. Alternatively, Matanos Aniyim are like Tzedakah. One must separate them immediately; if Aniyim are not around he must take them to Yerushalayim at the time of the Regel. Surely, he will find Aniyim there! However, if no Aniyim are around one may take them himself, he need not leave them for ravens. Perhaps here he discusses one who took them for an Oni. The Rambam did not say that Bal Te'acher applies to Matanos Aniyim. Perhaps he did not bother to elaborate. However, he listed other things, implying that it applies to them, but not to Matanos Aniyim. Perhaps this is because the Mitzvah of Bi'ur is at the end of three years. However, the Gemara connotes that Bal Te'acher applies to them.

Rosh (1:1): One transgresses Bal Te'acher immediately if he separates money for Tzedakah Stam (without specifying), like Nedarim and Nedavos of Korbanos. If one stipulates that he separates in order to give to Aniyim like he will see fit, he does not transgress Bal Te'acher if he delays to give it.

Poskim

Shulchan Aruch (YD 257:3): Tzedakah is a Neder. Therefore, if one said 'Alai to give a Sela to Tzedakah' or 'this Sela is for Tzedakah', he must give to Aniyim immediately. If he delays he transgresses Bal Te'acher, because he could give and Aniyim are found. If there are not Aniyim, he separates the money and leaves it until he finds Aniyim.

Mordechai (Bava Basra 491, partially brought in Beis Yosef DH veha'Mordechai): The Gemara (Erchin 6a) permits to change Tzedakah before it reaches the Gabai, because there is no loss to Aniyim. One can delay a day or a year; it is unreasonable to say that there is a limit. If one vowed to give to Aniyim of his choice, he transgresses immediately. This is because Aniyim are found and he could give to them; he did not vow to give to the Gabai. He cannot exempt himself by saying that he wants to give to others that will come, for if so he could exempt himself forever!

Rema: This refers to Tzedakah that he could give himself. But when people vow Tzedakah in the Beis ha'Keneses to give it to the Gabai, or other Tzedakah that we give to the Gabai, one does not transgress unless the Gabai demands from him and he refuses to give. In this case he transgresses immediately if there were Aniyim to whom the Gabai would have given.

Gra (7): When one vowed Tzedakah that we give to the Gabai, it is according to the Gabai's discretion. Therefore, he may not distribute it himself. Therefore, he is exempt until the Gabai requests from him.

Shach (6): If the Gabai demands from him and he refuses, he might transgress even if Aniyim are not found. Perhaps the Gabai borrowed his own or other money for Aniyim and needs to repay now. However, if one knows that the Gabai is collecting to save the money for later, he does not transgress now.

Rema (ibid.): If the Gabai does not know about the Neder, the Noder must tell him so the Gabai can demand from him. We say that 'Aniyim are found' only if they need the money now, but not if normally we would not give to them immediately. If one said 'I will give this Sela for Tzedakah to Ploni' he does not transgress until Ploni comes, even though other Aniyim are found.

Sha'ar ha'Tziyon (639:67): If one has poor guests and he delays the meal (waiting for the rain to stop on the first night of Sukos) perhaps he transgresses Bal Te'acher of Tzedakah.