What are the connotations of the words "Kol ha'Mitzvah"?
Rashi #1: It means simply 'all the Mitzvos'. 1
Rashi #2 (citing a Midrash): It implies that someone who begins to perform a Mitzvah should complete it. 2
Ramban: Even though Hashem had commanded Yisrael to observe the Mishpatim, 3 they should take care to observe all the Mitzvos, because it is as a result of keeping all the Mitzvos that they will merit living in the land and to flourish with regard to the fruit of the womb, the fruit of the animals and the fruit of the land.
Seforno: If they observe all the Mitzvos, they will succeed 4 in the three areas towards which people tend to strive - longevity, children and livelihood. 5
See Sifsei Chachamim.
Rashi: Because a Mitzvah is ascribed to the person who concludes it, like we find in Yehoshua, 24:32, where the Pasuk records how Yisrael buried the bones of Yosef in Sh'chem, in spite of the fact that Moshe was the one to take them out of Egypt and transport them through the desert for forty years. Da'as Zekenim: A person who begins a Mitzvah and does not complete it will bury his wife and children - like we find by Yehudah, who began to save Yosef but did not complete it, and soon afterwards his wife and sons died
What is the Torah referring to when it writes "Lema'an Tichyun u'Revisem"?
Rashi (in B'rachos, 48b): It is referring to living and increasing in Eretz Yisrael - because it is on the merit of the Torah and Mitzvos that Yisrael will inherit the land (and thrive in it).
Ramban: It is referring to life in this world, and an increase of children, animals and fruit.
Rosh #1: It is referring to life in the world to come, and an increase of children and money.
Rosh #2: It is referring to life in the days of Mashi'ach, and an increase of stature.
