You shall observe to do therefore as Hashem your G-d has commanded you. You shall not turn aside to the right hand or to the left. You shall walk in all the way which Hashem your G-d has commanded you, that you may live, and that it may be well with you, and that you may prolong your days in the land which you shall possess.
The Ohr Hachaim explains the double expression of תִ חְיוּן וְטוֹב לָּכ ם – live and it may be well with you refers to this world and the next. We should keep mitzvos in order that we live in this world, and it may be well with us in the next world. The long life they are promised is that they will not be banished from Eretz Yisroel.
However, this does not fit with one opinion in the Gemara (Kidushim 39b). Rabbi Yaakov said that there is no such thing as reward for a mitzvah in this world. If this is true, how is the Torah promising a reward in this world for tzadikim? The answer is, Rabbi Yaakov was only discussing a tzadik who is considered so because his mitzvos outweigh his aveiros. The Gemara says ‘anyone who performs one mitzva in addition to his other merits have goodness bestowed upon him in this world. However, a Beraysa teaches us: Anyone whose merits are greater than his sins is punished with suffering (in order to cleanse his sins in this world and enable him to merit full reward for his mitzvos in the World-to-Come.) Observers will think that he is like one who burned the entire Torah without leaving even one letter. Conversely, anyone whose sins are greater than his merits has goodness bestowed upon him in this world, and he appears like one who has fulfilled the entire Torah without lacking the fulfillment of even one letter of it. This shows us that mitzvos, even additional mitzvos, do not guarantee an easy life in this world.
Rava answered that the mishna and this beraysa indeed disagree, and the Beraysa is quoting the opinon of Rabbi Ya’akov, who says: There is no reward for the performance of a mitzva in this world, as one is rewarded for mitzvos only in the World-to-Come.
Rabbi Ya’akov is only discussing the case of someone who has both mitzvos and aveiros, but his mitzvos outweigh his aveiros. A complete tzadik has no aveiros at all, and he is not included in this limit.
Our possuk now reads that we should guard that which we are taught ‘You shall walk in all the way which Hashem your G-d has commanded you’. If we are careful not to make a single mistake, and to become complete Tzadikim, repairing any aveira that we have done, we will merit life and that things will even be well with us in this world. Even when the Torah promises length of days, we should not interpret it as referring to the world-to-come, as the Torah specifies that it will be in the land which you shall possess, on this world. If we act as complete Tzadikim, nothing will be in our way.
