Related for Megillah 4:6
קָטָן קוֹרֵא בַּתּוֹרָה וּמְתַרְגֵּם, אֲבָל אֵינוֹ פּוֹרֵס עַל שְׁמַע, וְאֵינוֹ עוֹבֵר לִפְנֵי הַתֵּיבָה, וְאֵינוֹ נוֹשֵׂא אֶת כַּפָּיו. פּוֹחֵחַ פּוֹרֵס אֶת שְׁמַע וּמְתַרְגֵּם, אֲבָל אֵינוֹ קוֹרֵא בַתּוֹרָה וְאֵינוֹ עוֹבֵר לִפְנֵי הַתֵּבָה וְאֵינוֹ נוֹשֵׂא אֶת כַּפָּיו. סוּמָא פּוֹרֵס אֶת שְׁמַע וּמְתַרְגֵּם. רַבִּי יְהוּדָה אוֹמֵר, כֹּל שֶׁלֹּא רָאָה מְאוֹרוֹת מִיָּמָיו, אֵינוֹ פּוֹרֵס עַל שְׁמַע:
A minor may read in the Torah [Some of the geonim say (that he may do so) only from shlishi on.] and translate; but he does not "parcel" the Shema [For he comes to effect the fulfillment of the obligation for others; and one who is himself not obligated in something cannot effect fulfillment of the obligation therein for others], and he may not act as prayer leader, and he may not lift his hands (in the priestly blessing) [if he is a Cohein, it not befitting the honor of the congregation to be dependent upon his blessing.] A pocheach [one whose clothes are torn and whose arms show ("naked and barefoot" - Isaiah 20:2) - is translated: "pacheach veyachef")] may "parcel" the Shema, [for he himself is obligated therein] and translate, but he does not read in the Torah, and he does not act as prayer leader, and he does not lift his hands (in the priestly blessing). [He does not read in the Torah because of the honor of the Torah. And so, with acting as prayer leader and lifting his hands, for it is demeaning to the congregation.] A blind man may "parcel" the Shema [For even though he does not see the luminaries, he benefits from them. For (through them) others see him and rescue him from obstacles.], and he may act as translator. R. Yehudah says: One who never saw the luminaries, [so that he never benefited from them] may not "parcel" the Shema. [The halachah is not in accordance with R. Yehudah.]