Halakhah zu Tehillim 130:78

One who stands before God in prayer should know that her existence and all of life’s blessings are dependent on God’s kindness and that God is not required to fulfill her requests; hence, she should stand before Him humbly. That is what the Sages meant when they said (Berakhot 10b): “One may not stand on a chair, on a stool, or on any other high place and pray, because there is no haughtiness before the Omnipresent, as it says (Tehilim 130:1): ‘From the depths I called You, Lord.’” The Talmud (Ta’anit 23b) relates a story about R. Yona who was known as a righteous person whose prayers were answered. When he was asked to pray for rain, he went to a low place in order to fulfill the verse: “From the depths I called You, Lord.” He prayed there until he was answered and rain began to fall. For that reason, it is customary in some congregations that the ḥazan’s place is lower. This also explains why the ḥazan is described as “descending before the ark” (“yored lifnei ha-teiva”).

The principal objection to this innovation is based, not upon insistence that the reader station himself within a specific area of the sanctuary, but rather upon the fact that the table or stand from which the Torah is read is commonly placed upon a bimah, or platform, which rises above the surrounding floor. Magen Avraham, Oraḥ Hayyim 90:3, notes that in previous times synagogues were designed so that the reader's stand was placed at the lowest point in the sanctuary with the worshippers' pews rising on an incline behind the reader. This feature of synagogue architecture, still retained in some European-style edifices, declares Magen Avraham, is designed to give literal expression to the sentiments recorded by the Psalmist, "From the depths have I called upon You" (Ps. 130:1). It is this custom which is the source of the talmudic idiom which speaks of the reader as "descending before the reader's stand." (See, however, Ma'adanei Yom Tov, Berakhot 10:8.) The rationale advanced by Magen Avraham is clearly applicable to individual worshippers as well. Yet the custom of standing in a low spot while engaged in prayer is limited to the reader alone. The custom arose in this form, explains Ketav Sofer, Oraḥ Hayyim, no. 19, because it is impossible to station all worshippers in a low area. Height and depth are relative concepts; if all pews were to be lowered, the result would be a level area. The reader was singled out and assigned the low position because he serves as the representative of the entire congregation.