“Im Bechukosai Taylaychu … ViNasati Gishmaychem B’Eto” If you will toil in Torah, Hashem promises that you will be the recipient of many Berachos – Rain in its time, the land will give its produce, peace etc. The Meforshim ask, why does the Torah promise a Davar Gashmi (materialistic reward) as a reward for learning Torah. Wouldn’t a spiritual reward be more appropriate? Secondly, the Gemora says, “Schar Mitzvah Bhay Alma Leka” –
The reward for Mitzvos are in the next world. How can the Torah promise rain and peace in this world for toiling in Torah? Thirdly, we know there is an Issur for an employer to hold back the wages of his employee. This is the Lav of Bal Talin – do not linger in paying your worker.
The posuk says, “BiYomo Titain Sichoro” – pay him on that day. Chazal compare Hashem to an employer who has hired workers (Klal Yisroel) to do his Mitzvos. The question arises, how then can he pay them in Olam Haba, isn’t that prolonging his payment to them? Isn’t that the Isur of Bal Talin? The Gemora in Bava Metziah (110b) says that the Isur of Bal Talin is only if the employer hired the worker himself. However, if he made a Shliach to hire the worker, the Lav of Bal Talin does not apply. Hashem did not give the Mitzvos directly to Klal Yisroel, rather he appointed Moshe as his Shliach. Therefore, Hashem is not violating Bal Talin when giving us reward in Olam Haba. There are however 2 Mitzvos which Hashem gave directly to Klal Yisroel; that is the Mitzvos of Anochi and Lo Yihyeh Licha (the first 2 commandments of the Aseres HaDibros). Since they were given directly to Klal Yisroel, there is an Issur Of Bal Talin to wait until Olam haba to give Klal Yisroel their reward. It is for that reason that there is reward on this world.
All reward on this world is because of those 2 Mitzvos which were given directly to Klal Yisroel. We can explain with this the connection between the last Mishnah in Senhedrin and the first Mishnah in Avos. Senhedrin ends with the statement – “Kol Yisroel Yaish LaHem Chelek BaOlam Haba.” Avos starts with “Moshe Kibail Torah MiSinai” .
Why do all Jews get rewarded in Olam haba? Because Moshe received the Torah in Sinai.
Since he was a Shliach from Hashem to Klal Yisroel, there is no Issur of Bal talin and Hashem can give his reward in the next world!