Shekalim2: 5
מוֹתַר שְׁקָלִים חֻלִּין. מוֹתַר עֲשִׂירִית הָאֵיפָה, מוֹתַר קִנֵּי זָבִין, קִנֵּי זָבוֹת, וְקִנֵּי יוֹלְדוֹת, וְחַטָּאוֹת וַאֲשָׁמוֹת, מוֹתְרֵיהֶן נְדָבָה.  זֶה הַכְּלָל: כֹּל שֶׁהוּא בָא לְשֵׁם חַטָּאת וּלְשֵׁם אַשְׁמָה, מוֹתָרָן נְדָבָה.  מוֹתַר עוֹלָה לְעוֹלָה. מוֹתַר מִנְחָה לְמִנְחָה. מוֹתַר שְׁלָמִים לִשְׁלָמִים. מוֹתַר פֶּסַח לִשְׁלָמִים.  מוֹתַר נְזִירִים לִנְזִירִים; מוֹתַר נָזִיר לִנְדָבָה.  מוֹתַר עֲנִיִּים לַעֲנִיִּים; מוֹתַר עָנִי לְאוֹתוֹ עָנִי.  מוֹתַר שְׁבוּיִם לִשְׁבוּיִם; מוֹתַר שָׁבוּי לְאוֹתוֹ שָׁבוּי.  מוֹתַר הַמֵּתִים לְמֵתִים; מוֹתַר הַמֵּת לְיוֹרְשָׁיו. רַבִּי מֵאִיר אוֹמֵר: מוֹתַר הַמֵּת יְהֵא מֻנָּח עַד שֶׁיָּבֹא אֵלִיָּהוּ. רַבִּי נָתָן אוֹמֵר: מוֹתַר הַמֵּת בּוֹנִין לוֹ נֶפֶשׁ עַל קִבְרוֹ.
The remainder of [funds set aside for] the half shekels is unconsecrated.  The remainder of [funds set aside for the purchase of] the tenth of an ephah [meal-offering]; the remainder of [funds set aside for the purchase of] bird-offerings of zavim, zavos, and women after childbirth; [the remainder of funds set aside for the purchase of] sin-offerings and guilt-offerings —- these remainders are [to be placed in the collection chest marked] “Donative Offering.”  This is the gen-eral rule: Whatever [money] has been set aside for [the purchase of sacrifices to atone for] a sin or for guilt —- its remainder is [to be placed in the collection chest marked] “Donative Offering.”  The remainder of [funds set aside for] a burnt-offering is [to be used] for [the purchase of] a burnt-offering. The remainder of [funds set aside for] a meal-offering is [to be used] for [the purchase of] a meal-offering. The remainder of [funds set aside for] a peace-offering is [to be used] for [the purchase of] a peace-offering. The remainder of [funds set aside for] a pesach-offering is [to be used] for [the purchase of] a peace-offering.  The remainder of [funds contributed for the offerings of] nazirites is [to be used] for nazirites; but the remainder of [funds contributed for the offerings of] a [specific] nazirite is [to be placed in the collection chest marked] “Donative Offering.”  The remainder of [funds contributed for distribution to] poor people is [to be used] for poor people; but the remainder of [funds contributed for the sake of] a [specific] poor man is [to be given] to that poor man.  The remainder of [funds contributed for the ransom of] captives is [to be used] for [the ransom of] captives; but the re-mainder of [funds contributed for the ransom of] a [specific] captive is [to be given] to that captive.  The remainder of [funds contributed for the burial of] the dead is [to be used] for [the burial of] the dead; [but] the remainder of [funds contributed for the burial of] a [specific] dead person is [to be given] to his heirs. R’ Meir says: The remainder of [funds con-tributed for the burial of] a [specific] dead person is to be held in escrow until Elijah shall come. R’ Nosson says: [With] the remainder of [funds contributed for the burial of] a [specific] dead person they build a monument for him on his grave.
Shekalim3: 1
בִּשְׁלשָׁה פְרָקִים בַּשָּׁנָה תּוֹרְמִין אֶת הַלִּשְׁכָּה: בִּפְרוֹס הַפֶּסַח, בִּפְרוֹס עֲצֶרֶת, בִּפְרוֹס הֶחָג, וְהֵן גְּרָנוֹת לְמַעְשַׂר בְּהֵמָה, דִּבְרֵי רַבִּי עֲקִיבָא.  בֶּן עַזַּאי אוֹמֵר: בְּעֶשְׂרִים וְתִשְׁעָה בַּאֲדָר, וּבְאֶחָד בְּסִיוָן, וּבְעֶשְׂרִים וְתִשְׁעָה בְּאָב.  רַבִּי אֶלְעָזָר וְרַבִּי שִׁמְעוֹן אוֹמְרִים: בְּאֶחָד בְּנִיסָן, בְּאֶחָד בְּסִיוָן, בְּעֶשְׂרִים וְתִשְׁעָה בֶּאֱלוּל. מִפְּנֵי מָה אָמְרוּ ,,בְּעֶשְׂרִים וְתִשְׁעָה בֶּאֱלוּל”, וְלֹא אָמְרוּ ,,בְּאֶחָד בְּתִשְׁרֵי”? מִפְּנֵי שֶׁהוּא יוֹם טוֹב, וְאִי אֶפְשָׁר לְעַשֵּׂר בְּיוֹם טוֹב, לְפִיכָךְ הִקְדִּימוּהוּ לְעֶשְׂרִים וְתִשְׁעָה בֶּאֱלוּל.
At three periods of the year they withdraw [funds] from the [treasury] chamber; fifteen days before Pesach, fifteen days be-fore Shavuos, and fifteen days before Succos. And these are also the designated dates for the animal tithe —- [these are] the words of R’ Akiva.  Ben Azzai says: [The three periods are] on the twenty-ninth of Adar, on the first of Sivan, and on the twenty-ninth of Av.  R’ Elazar and R’ Shimon says: [The three periods are] on the first of Nissan, on the first of Sivan, and on the twenty-ninth of Elul. Why did they say “on the twenty-ninth [of Elul]” instead of saying “on the first of Tishrei”? —- because that [day] is a festival, and one may not tithe on a festival, therefore they advanced it to the twenty-ninth of Elul.