104. Where to Stand
18:7 A person should not support himself on anything while saying Shemoneh Esrei, not a little bit. If one is sick – even if not seriously ill – he may pray seated or lying down (on his side – OC 94:6), so long as he can focus his attention. If one cannot pray verbally, he should think about the words of the prayers in his heart.
18:8 A person should not hold anything in his hands while saying Shemoneh Esrei with the exception of his siddur or machzor. One should mark the places he’ll need in his siddur so that he won’t have to go searching in the middle of his prayers. There shouldn’t be anything between a person and the wall as we see from King Chizkiyahu, who turned to the wall to pray in Isaiah 38. In order to be considered an obstacle between him and the wall, an object would have to be at least ten handbreadths high by four handbreadths wide. (A handbreadth is about three inches.) Also, a permanently-fixed structure, like a cabinet (or benches – Mishnah Brurah 90:68), is not considered an obstacle for this purpose, nor is another person. (One can be any distance from the wall while praying; if an obstacle is more than four cubits/six feet from him, it is of no consequence – Mishnah Brurah 90:64.) If one cannot avoid something coming between him and the wall, it’s okay; in such case, a person can merely close his eyes or look in the siddur to avoid distractions. One may not pray facing a picture; if unavoidable, he must close his eyes. One may also not pray facing a mirror; in this case, closing the eyes doesn’t help. It is far preferable to pray in a private (enclosed) location, which is more conducive to the proper mind set, and not somewhere open, like a field. If a person is traveling, he may pray in a field, though he should try to pray among the trees.