It is a mitzvah to choose a synagogue and pray there regularly. One should not change his place of prayer needlessly. This was the custom of Avraham Avinu who designated a place to pray, as it is written (Genesis 19:27), “Avraham woke up early in the morning [to go] to the place where he had stood before God,” implying that he had a regular place where he would stand before Hashem. The designation of a place of prayer illustrates that one’s connection to Hashem is absolute. Everything else in the world can change, but one’s connection to Hashem is the most permanent and stable reality and should therefore transpire in a permanent place. The Chachamim say, “Whoever assigns a set place to pray, the God of Avraham helps him, and his enemies fall beneath him” (Berachot 6b, 7b; see Maharal, Netiv HaAvodah, chapter 4).
However, it is not sufficient to designate a synagogue in which to pray. According to most poskim, even within the synagogue, every person must designate a permanent place to pray (Shulchan Aruch 90:19). The primary importance of establishing a place to pray pertains to the recital of the Amidah prayer (Ben Ish Chai, Miketz 4). When there are benches that move back and forth slightly, it is not necessary to measure one’s seat in centimeters, rather the whole radius of four amot (approximately two meters; approx. 6.56 ft) is considered one place. However, when every person has his own chair, l’chatchilah it is best to sit specifically in one’s regular seat and to pray the Amidah near it.
Sometimes a guest sits in the seat of one who prays in the synagogue regularly. If there is no reason to suspect that the guest will be insulted, he may be asked to move to another seat. However, if there is a chance he may be hurt, it is better to sit elsewhere instead of possibly humiliating him. Ideally, the gabba’im (synagogue coordinators) should greet the guests and find them seats.
The mitzvah to establish a set place to pray does not obligate a Jew to live his whole life in the same location in order to continue praying in his designated seat. Rather, if a person needs to move to another home, or thinks he may be able to pray with more kavanah in a different synagogue, he should change his place of prayer, and choose a new regular seat for himself.
If a minyan does not assemble in one’s regular place of prayer, he should go pray elsewhere, for the virtue of praying in a minyan is more important than the virtue of establishing a regular place to pray. If, while one is praying in his regular seat, his concentration is disrupted by children playing nearby, it is preferable to switch to a different seat for the duration of that prayer service (Aruch HaShulchan 90:22; Kaf HaChaim 118).
A person who needs to recite Shacharit in one area and Minchah and Ma’ariv in another and designates one place to pray Shacharit and a different place for Minchah and Ma’ariv is still considered one who has established a place for prayer. Similarly, one who needs to designate a place in one synagogue on Shabbat and in another on weekdays is still considered establishing a place for prayer (Halichot Shlomo 5, note 2).
. The Mishnah Berurah 90:60, based on the Magen Avraham, writes that within four amot is considered one place, because ones place cannot be measured exactly. However, it seems that when each person is assigned his own specific seat, the feeling of the permanent place pertains to that particular chair, as is written in the responsa of Yosef Ometz, 30. Nonetheless, if a guest takes a person’s place and there is an empty seat next to him, in order not to make the guest feel bad, he should sit in the empty seat alongside the guest, since as long as he is within four amot, he is considered to be sitting in his regular seat.
. However, the Eshel Avraham Butshatsh, Tinyana Edition, 90:19, is uncertain about this ruling. In extenuating circumstances, one may rely on that uncertainty and pray in his permanent place rather than in a minyan. Also see Halichot Shlomo 5:2, who writes that if a person is late for prayer, it is preferable that he skip Pesukei d’Zimrah in order to pray in his regular synagogue, instead of going to a different place where he could pray all of Pesukei d’Zimrah.