Repeating the Words of the Prayers
Question
Is it ok for the Chazzan to repeat the words of the prayers?
Answer
Shalom!
Thank you for your question.
It is forbidden to repeat the words of the prayers. This is especially true if such repletion includes the name of G-d, as it is said to appear as if one is praying to two different gods. The classic example of this is from the Mishna (Berachos 33b) where it says that one who says “Modim, Modim” is to be censured. Such a person is suspected of being a heretic and giving thanks to two different gods. Repeating the word Shema is also explicitly forbidden and appears to be addressing two different gods.
Le,halocho, repeating word of the prayers just to make them fit into a chosen tune is unbecoming and shows an irreverence to the holiness of the prayers. Repeating words can also be a problem of “hefsek” the ban on making unnecessary interruptions in the prayers. According to kabbala the prayers were explicitly written with an exact number of words for all kinds of mystical considerations and repeating words adds to this number thereby ruining the mystical benefits.
If one did not have the proper concentration and intention when reciting the Shema one is to repeat the verse. One is to do so quietly if praying in a congregation but one who is alone may recite it out loud just like the first time.
That being said, one is occasionally permitted to repeat entire prayers. For example, one who has trouble falling asleep after reacting the “bedtime Shema” is permitted to recite the Shema over and over again until one falls asleep.
In summary: As a general rule one is always to avoid repeating words in the prayers. There are some minor exceptions where it is permitted.
Source
OC 61 and 63 with commentaries; Aruch Hashulchan 338:8; Igrot Moshe OC 2:22; Maharam Schick, OC 31.