וְהָי֞וּ הַדְּבָרִ֣ים הָאֵ֗לֶּה אֲשֶׁ֨ר אָנֹכִ֧י מְצַוְּךָ֛ הַיּ֖וֹם עַל־לְבָבֶֽךָ׃
I niechaj będą słowa te, które ci przykazuję dzisiaj, na sercu twojém!
Mishnah Berakhot
One who recites the Shema without causing it to be heard by his own ear, he has fulfilled his obligation. Rabbi Yose says: he has not fulfilled his obligation. If he recited it without pronouncing the letters succinctly, Rabbi Yose says he has fulfilled his obligation. Rabbi Judah says: he has not fulfilled his obligation. If he recites it out of order, he has not fulfilled his obligation. If he recites it and makes a mistake he goes back to the place where he made the mistake.