סימן קכב סעיף ב
נוֹהֲגִין שֶׁאֵין מְבָרְכִין שֶׁהֶחִיָּנוּ בַּיָמִים אֵלּוּ. וְלָכֵן אֵין קוֹנִין וְאֵין לוֹבְשִׁין בֶּגֶד חָדָשׁ, מִשּׁוּם דְּהָיָה צָרִיךְ לְבָרֵךְ שֶׁהֶחִיָּנוּ. וְעַל פִּדְיוֹן הַבֵּן, מְבָרְכִין שֶׁהֶחִיָּנוּ, שֶׁלֹּא לְהַחְמִיץ אֶת הַמִּצְוָה. וְעַל פְּרִי, יֵשׁ לְהָקֵל לְבָרֵךְ שֶׁהֶחִיָּנוּ בַּשַׁבָּת, אוֹ אֲפִלּוּ בְּחֹל, אִם לֹא יִמָצֵא פְּרִי זֶה לְאַחַר תִּשְׁעָה בְּאָב. לֹא יַכּוּ הַתַּלְמִידִים אוֹ הַבָּנִים בְּיָמִים אֵלּוּ.
It is customary not to say the berachah, Shehecheyanu during these days.3According to the Vilna Gaon, this is an unnecessary stringency. Taz is also doubtful about this custom. On Shabbos, therefore, you need not be concerned, and the berachah Shehecheyanu may be said over a new fruit or on new clothing. (Ibid. 551:98) Therefore, you should not buy or put on a new garment, since that would make it necessary for you to say the berachah, Shehecheyanu. But at the occasion of a Pidyon haben, (redemption of the firstborn), Shehecheyanu must be said, so as not to postpone the fulfillment of the mitzvah. Concerning a new fruit, we are lenient and say Shehecheyanu on Shabbos4See note 3. or even on a weekday,5According to Rav Akiva Eiger, this rule also applies to Rosh Chodesh. (Shaar Hatzion 551:98) if this fruit will not be available6This refers to a situation where the fruit cannot be kept until Shabbos because of spoilage. If, however, the fruit can be preserved until Shabbos, it is best to do so. (Mishnah Berurah 551:101) after Tishah beAv. Teachers should not strike students, and parents should not strike their children during these days.
תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)