Halakhah su Isaia 38:2

You should select a synagogue or a Beis Midrash in which to pray regularly. You also should designate for yourself a specific place for prayer.²⁶I.e. within the synagogue or Beis Midrash. The area within a radius of four amos²⁷I.e., of your designated spot. is [still] considered "your" place. It is preferable to designate a place near a wall, [if possible], as did King Chizkiyahu, as it is written: "And Chizkiyahu turned his face to the wall etc."²⁸Isaiah 38:2. When praying, you should not stand or sit near an evil person. When you pray in your house [privately] you should also designate a place for yourself so that you will not be disturbed by the members of the family.

Nothing should be held in the hand while praying the Shemoneh Esrei²²This law is also applicable when reading the Shema and Pesukei Dezimrah. except the Siddur or Machzor, if needed. Before praying, you should mark the places to be read in the Siddur or Machzor, avoiding the need to search for them in the midst of your prayer. There should be no barrier between you and the wall, as it is said: "And Hezekiah turned his face toward the wall and he prayed."²³Isaiah 38:2. Something is considered a barrier only if it is ten tefachim high²⁴See glossary. and four tefachim wide, but a small[er] article is not considered a separation. Even a large article, when installed permanently, such as a chest or cabinet, is not considered a separation; neither is a person considered a barrier.²⁵When praying in a synagogue it is often impossible to actually stand in front of a wall, since there are usually people in front of you. Thus we are told that a person is not considered a barrier. When there is no other choice,²⁶Except to pray where there is a separation between you and the wall. you need not be concerned, since you close your eyes [anyway] or pray from a Siddur, so that your concentration is not disturbed. You should also not pray in front of a picture, but should it happen that you are praying in front of a garment or decorated wall,²⁷Some walls are decorated with designs or murals which are distracting. you should [certainly] close your eyes. It is forbidden to pray in front of a mirror, even with your eyes closed. You should not pray in an open space, such as a field, for praying in an enclosed area causes one to be imbued with awe of the King, and the heart to be contrite and humbled. When traveling on the road, it is permissible to pray in the field; if possible however, you should pray among the trees.