“With your mouth,” refers to tzedaka. Rava said: Regarding Tzedakah one is liable [for delaying the fulfillment of a vow] immediately. Why? Because poor people are present [who need the money.]
Based on this Gemara, Rambam writes: A Tzedakah pledge is a form of a vow, therefore if one vows to give a selah to Tzedakah or if he commits to give a particular coin to Tzedakah he is obligated to give the pledged money to the poor immediately. If he delays giving the money he violates the prohibition of בל תאחר since he has the ability to give the money and poor people are present. If, however, poor people are not present one should set aside the money until a poor person is available. This ruling is cited by Shulchan Aruch.
Rav Betzalel Stern questions whether one violates בל תאחר every day he does not fulfill his pledge or whether he violates the prohibition only once and the violation is ongoing. His conclusion is that once a poor person comes to collect the money and the donor does not fulfill his vow, he violates the prohibition and that violation continues until he fulfills his vow. There is a dispute whether the new refusal constitutes a new violation or a continuation of the original violation if, after refusing to give Tzedakah to the first poor person, he subsequently refuses to fulfill his vow when a second and third poor person asks for the money.
Rav Moshe Isserles, the Rema, qualifies this ruling and states that it applies only when the donor is going to distribute the money to the poor himself. If, however, the pledge was made to a shul or other charitable organization, one does not violate בל תאחר, even if poor people are present, until the Gabbai Tzedakah claims the money. Only when the Gabbai Tzedakah claims the money and the donor refuses to fulfill his vow is the prohibition violated. Furthermore, if the Gabbai Tzedakah is unaware of the pledge the donor is obligated to inform him that a pledge was made so that he will be able to claim the money.
Seudas Shabbos
Chofetz Chaim states that if one has a poor guest to his home for the Shabbos meal, one is obligated to eat immediately upon returning from shuel to avoid bal te’acher. One should not delay by saying Shalom Aleichem or singing since the meal given to the poor is Tzedakah. Thus, one cannot tarry or stall at all. The Chofetz Chaim himself was accustomed when he had poor guests, to say Shalom Aleichem during the meal. Further, he would not stay longer in shuel, even to engage in Divrei Torah.
“With your mouth” (Devarim 23,24) refers to Tzedakah
Apparently upon death one cannot take anything with him except acts of Mitzvos, good deeds and Tzedakah. A parable of understanding: When one wishes to move across a border, one does not have permission to take any wealth or property. Thus, a person would transfer the value to a precious stone and swallow it. After crossing the border, the person would spit up the stone. So, a person crosses the border of death one can only take acts that can be swallowed. Thus, Lavan checked the mouth of Yaacov. (Orach Yesharim)
