אורח חיים צ׳Orach Chayim 90

Se’if 1א׳

הַמִּתְפַּלֵּל לֹא יַעֲמֹד לֹא עַל גַּבֵּי מִטָּה, וְלֹא עַל גַּבֵּי כִּסֵא, וְלֹא עַל גַּבֵּי סַפְסָל וַאֲפִלּוּ אֵינָן גְּבוֹהִין ג' (בֵּית יוֹסֵף בְּשֵׁם מַהֲרִי"א), וְלֹא עַל גַּבֵּי מָקוֹם גָּבוֹהַּ, אֶלָּא אִם כֵּן הָיָה זָקֵן אוֹ חוֹלֶה, אוֹ שֶׁהָיָה כַּוָנָתוֹ לְהַשְׁמִיעַ לַצִּבּוּר.

A Place Appropriate to Pray. And to Pray with the Congregation and the Law of One Who Travels, containing 27 s'ifim One who prays should not stand on a bed, a chair, a bench even if they are not 3 [hand-breadths tall] (Beit Yosef in the name of Mahari"ya), and not on top of any high place, except if one was old or sick [and thus cannot descend], or if one's intent was to make the congregation hear one [i.e.: a chazzan].

Se’if 2ב׳

שִׁעוּר מָקוֹם גָּבוֹהַּ שֶׁאָמְרוּ ג' טְפָחִים. הָיָה גָּבוֹהַּ ג' וְיֵשׁ בּוֹ ד' אַמּוֹת עַל ד' אַמּוֹת, הֲרֵי הוּא כַּעֲלִיָּה וּמֻתָּר לְהִתְפַּלֵּל בּוֹ. וְכֵן אִם הָיָה מֻקָּף מְחִצּוֹת, אַף עַל פִּי שֶׁאֵין בּוֹ ד' עַל ד' מֻתָּר לְהִתְפַּלֵּל בּוֹ, שֶׁאֵין גָּבְהוֹ נִכָּר כֵּיוָן שֶׁחָלַק רְשׁוּת.

The measure of a high place is three hand-breadths. If it is three [hand-breadths] tall, and it has an area of four cubits by four cubits, it is like an upper story and it is permissible to pray upon it. And so too, if it was surrounded by dividers, even if it is not an area of four [cubits] by four [cubits], it is permissible to pray upon it, for its height is not recognized once its domain is separated.

Se’if 3ג׳

הָאֻמָּנִין שֶׁעוֹשִׂין מְלָאכָה לְבַעַל הַבַּיִת יְכוֹלִין לְהִתְפַּלֵּל בְּרֹאשׁ הַזַּיִת וּבְרֹאשׁ הַתְּאֵנָה, וְאֵין בָּזֶה מִשּׁוּם לֹא יַעֲמֹד עַל גַּבֵּי מָקוֹם גָּבוֹהַּ וְיִתְפַּלֵּל, דְּכֵיוָן שֶׁעָלוּ לַעֲשׂוֹת מְלַאכְתָּם, הָוֵי כְּמִי שֶׁעוֹלֶה לַעֲלִיָּה. וּבִשְׁאָר אִילָנוֹת צְרִיכִים לִירֵד, וְהַטַּעַם שֶׁנִּשְׁתַּנָּה הַזַּיִת מִשְּׁאָר אִילָנוֹת, מִפְּנֵי שֶּׁיֵּשׁ לָהֶם עֲנָפִים הַרְבֵּה יוֹתֵר מִשְּׁאָר אִילָנוֹת, וְיֵשׁ טֹרַח גָּדוֹל בַּעֲלִיָּתָם וּבְירִידָתָם, וְיִתְבַּטְּלוּ מִמְּלַאכְתָּם וּלְפִיכָךְ אָמְרוּ שֶׁיִּתְפַּלֵּל שָׁם. אֲבָל שְׁאָר אִילָנוֹת דְּלֵיכָּא בִּטּוּל, יֵרְדוּ. וּבַעַל הַבַּיִת, אֲפִלּוּ מֵרֹאשׁ הַזַּיִת וְהַתְּאֵנָה צָרִיךְ לִירֵד לְהִתְפַּלֵּל, דְּהָא אֵינוֹ מְשֻׁעְבָּד לִמְלָאכָה שֶׁהוּא בִּרְשׁוּת עַצְמוֹ. וְאִם הֵקֵלּוּ אֵצֶל פּוֹעֲלִים מִפְּנֵי בִּטּוּל מְלָאכָה, לֹא הֵקֵלּוּ אֵצֶל בַּעַל הַבַּיִת.

The laborers doing labor for the house-owner may pray on the top of the olive tree and at the top of the fig tree, and [the rule of] 'One should not stand on a high place and pray' does not apply in this [case]. Since they have ascended to do their labor, behold they are like someone who ascended to the second story of a house. But with regard to all other trees, it is necessary to descend. And the reason that [the rule of] the olive tree is different from all other trees is because they have many more branches than other trees and thus it is a hardship to ascend them and descend them, and they [the laborers] will be interrupted from their work. And therefore, they said that they should pray there. But regarding the other trees, which do not cause interruptions from work [due to the ease of descending and ascending], they should descend. And the house-owner (ie. the employer), even at the top of the olive or date tree, must descend to pray, for he is not indebted to [his] labor, in that he is on his own property. And even though they were lenient regarding workers because of breaks from work, they were not lenient regarding the house-owner.