Related for Megillah 50:10
ואלו נקרין ולא מתרגמין (רעבד"ן סימן) מעשה ראובן נקרא ולא מתרגם ומעשה ברבי חנינא בן גמליאל שהלך לכבול והיה קורא חזן הכנסת (בראשית לה, כב) ויהי בשכון ישראל ואמר לו למתורגמן (הפסק) אל תתרגם אלא אחרון ושיבחוהו חכמים
The following are read but not translated (Mnemonic: R’E’B’D’N’). The incident of Reuben is read but not translated. On one occasion R. Hanina b. Gamaliel went to Kabul, and the reader of the congregation read, “And it came to pass when Israel dwelled” (Genesis 35:22), and he said to the translator: Translate only the latter part of the verse, and the sages praised him.
Tosefta Megillah
One who leads the responsive recitation of the Shema, or blesses over fruit or over matzah, behold, he should not answer "amen" after himself. If he answered ["amen" after his own prayer], behold, this is how ignoramuses act. We do not answer with either an "orphaned amen" (i.e., where one does not know to what blessing he is saying "amen"), or a "truncated [amen]" (i.e., where one does not pronounce the entire word). Ben Azzai says, one who answers with an "orphaned amen" -- his children will be orphaned; with a "truncated [amen]," his days will be truncated. But whoever prolongs [his amen], his days and years will be prolonged.
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