Together, the three paragraphs of
Shema contain 245 words. The Chachomim instituted the repetition of the final three words--
Hashem
E-lokeichem emes--to bring the number of words to 248. The 248 words correspond to, and serve to heal, the 248 limbs of the human body. The
chazan's repetition counts for the congregation as well. The
poskim discuss whether the
chazan should say the word
emes quietly, as part of his own recitation of
Shema, before he repeats the entire phrase out loud. Some
poskim suggest that when the
chazan repeats the phrase immediately after he completes his own
Shema he should omit the word
emes, but when he completes
Shema ahead of the congregation and has to wait for them, he should add the word
emes.
(
סעיף ג וס"ק ו ו־ח; ביאורים ומוספים דרשו, 4)