סימן יח סעיף יח
אָסוּר לֵישֵׁב בְּתוֹךְ דּ' אַמּוֹת שֶׁל הַמִּתְפַּלֵּל תְּפִלַּת שְׁמֹנֶה עֶשְׂרֵה, בֵּין מִלְּפָנָיו בֵּין לְאַחֲרָיו בֵּין מִן הַצְּדָדִין. וְאִם הָיּוֹשֵׁב עוֹסֵק גַּם כֵּן בְּמַה דְּשַׁיָּךְ לְסֵדֶר הַתְּפִלָּה מֻתָּר. וְיֵשׁ מְקִלִּין, דַּאֲפִלּוּ אֵינוֹ עוֹסֵק בְּעִנְיְנֵי תְּפִלָּה, אֶלָּא שֶלּוֹמֵד תּוֹרָה בְּפִיו אֵינוֹ צָרִיךְ לְהִתְרַחֵק. וְהַיָּרֵא דְּבַר ה' לֹא יֵשֵׁב לִפְנֵי הַמִּתְפַּלֵּל תְּפִלַּת שְׁמוֹנֶה עֶשְׂרֵה כִּמְלֹא עֵינָיו, אֲפִלּוּ אוֹמֵר קְרִיאַת שְׁמַע. אֲבָל לְאַחֲרָיו וְלַצְּדָדִין אֵין לְהַקְפִּיד. וְלַעֲמֹד מֻתָּר בְּכָל עִנְיָן אֲפִלּוּ לְפָנָיו.
It is forbidden to sit within four amos in front, behind or along side of a person praying the Shemoneh Esrei prayer.59I.e., in a circle around the person praying within a radius of 6 to 8 feet. But, if the person seated is also engaged in that which is related to the "Order of the prayers,"60Though he is not involved in Shemoneh Esrei or Kerias Shema but in other parts of the synagogue service which are only a minhag (custom). he is permitted [to remain seated]. There are [poskim] who are lenient [and permit him to remain seated] even if he is not engaged in matters relating to prayer, but is only studying Torah orally.61Reading aloud or speaking words of Torah. But a God-fearing man should not sit in front of a person praying the Shemoneh Esrei prayer within his line of vision62Even if the distance is greater than four amos. even if he (the seated person) is saying Kerias Shema. But [to be seated] behind or alongside [a person praying Shemoneh Esrei] is not objectionable, and it is permitted to stand in all situations63All the objections mentioned above refer to sitting only. even in front of [the person praying].
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.)