A person who stands before HaKadosh Baruch Hu in prayer should know that his life is dependent on Hashem’s kindness, and should therefore stand before Him humbly. That is what the Chachamim meant when they said (Berachot 10b), “A person may not stand on a chair, on a stool, nor on any other high place and pray, because there is no haughtiness before the Omnipresent, as it says (Psalms 130:1), ‘From the depths I called You, Hashem.’” In contrast, a synagogue must be built on the highest location in the city, in order to confer respect and superiority to the synagogue (Shabbat 11a; Peninei Halachah Likutim I 6:4). However, the person praying must stand before God in humility, and therefore standing on a high place is forbidden. The Talmud (Ta’anit 23b) relates a story about Rabbi Yonah who was known as a righteous person whose prayers were answered. When he was requested to pray for rain, he went to a low place in order to fulfill the words, “From the depths I called You, Hashem.” There he prayed until he was answered and rain began to fall. For that reason it is customary in some congregations to lower the chazan’s place, which explains why the chazan is described as “descending before the ark.”
As a rule, the Chachamim prohibited an elevated place higher than three tefachim (24 cm; approx. 9.45 in) above the ground. However, in practice, it is forbidden to pray even on a less elevated place, for two reasons. First, a person standing on a stepstool or rock, even only one tefach in height, is worried about losing his balance and cannot have the proper kavanah while praying. Second, if the floor is even, elevating oneself on pillows, cushions, or anything else, suggests a sense of haughtiness and it is improper to pray in such a manner. Nevertheless, praying on rugs and mats which are normally laid out on the floor is permitted l’chatchilah. Likewise, whoever prays on uneven ground may stand on the elevated parts, as long as they are not three tefachim higher than the rest of their surroundings.
A sick or elderly person who has trouble getting out of bed may pray in bed, even though it is elevated from the ground.
If the high place stands on its own – for instance, it is wider than four amot by four amot (approximately two meters by two meters or 6.56 ft x 6.56 ft) – one is permitted to pray on it, because it is not measured in relation to other places, rather it is considered its own domain. Therefore, when a synagogue has two levels, if the higher floor is at least four amot by four amot, it is permissible to pray on it.
Even an area which is smaller than four amot is considered to be its own domain if it is surrounded by partitions, and it is permissible to pray on it. This is the law regarding congregations in which it is customary to build a bimah (pulpit) in the center of the synagogue on which the chazan stands. If the bimah is surrounded by partitions, or is larger than four amot by four amot, then it is permissible to pray on it, since we do not measure its height in relation to other parts of the synagogue. However, someone who prays there does not fulfill the enhancement of the mitzvah in the verse, “From the depths I called You, Hashem.” Even so, these congregations prefer to build a bimah for the chazan and forsake the enhancement of “descending before the ark” so that the congregation can hear the chazan’s voice clearly.