ציטירנדיקער פּירוש אויף דברים 11:21

יחזור למקום שטעה – If between each section [of the Shema] he erred and did not know on which section he had interrupted (the appropriate order), and to which paragraph’s beginning he should return to, he should go back to the first interval – which is “והיה אם שמוע” (Deuteronomy 11:13-21). And Maimonides states that this is the first sentence: “ואהבת את ה' אלהיך” (Deuteronomy 6:5), and if he is in the middle of a section, he should stop [assuming that] he knows which section (of the Shema) that he is in, but if he doesn’t know which place and from which section he is in, he should stop and return to the beginning of that section. If he was reciting: “וכתבתם [על מזוזות]” and did not know if it was referring did not know if it was referring to “and you shall inscribe them” from the first section of the Shema (Deuteronomy 6:9) or the second section of the Shema (Deuteronomy 11:20), he should go back to the first mention of “you shall inscribe them” (Deuteronomy 6:9). But if he became doubtful after he had begun (the concluding verse of the second section of the Shema), “to the end that you and your children may endure” (Deuteronomy 11:21), he should not go back, since he is following the natural flow of the language [of the Shema].

ואל ימות ויהי מתיו מספר, may he not die out in this life on earth so that his numbers will become too insignificant. (Yaakov already described people who are few in numbers as being in danger of being wiped out, Genesis 34,30) Moses prays that the tribe of Yehudah be included in the blessing of Deut. 11,21 “so that you will enjoy many years on the earth, etc.”

למען תחזקו ”in order that you be strong;” Moses does not tell the people to observe G–d’s laws in order that they will become strong (physically), for if that were the reason they would be fulfilling the Torah for the sake of the reward in store for them. This is not the proper motive. (Compare Ethics of our fathers chapter 1, mishnah 3) The interpretation of this line is as follows: “perform the commandments out of a feeling of love for the Lord.” The word למען, here does not mean: “in order that,” just as it does not mean “in order that” in verse 21 of our chapter where we read: למען יאריכון ימיך, in the Ten Commandments in chapter 5,16. It means that the reason you must be strong is in order that you can fulfill the commandment required of you. The word is not linked to what follows, but describes a requisite for successful performance of the Torah being not fear of G–d but love of G–d.