Why is there a difference between the change of name of Yaakov and Avraham's name change? Is it forbidden to call Avraham Avram? Does the mitzva of shema need intent? Why type of intent? Is one allowed to speak at all during shema and its blessings? On what does it depend? What is the significance of the order of the sections of shema? Does one need to say shema in hebrew or can one say it in any language? There is a debate and each brings proof texts. Until what section of shema does one need intent? Can one say shema in one's heart or does one need to say the words? Does one need to hear the words? Can one say only the sentence "shema..." and fulfill one's obligation? It is told of Rabbi Yehuda Hanasi that he did that - why?