The day after the Korach fiasco ended, Bnei Yisrael complained that Moshe and Aharon were responsible for everyone's death. Hashem then told Moshe, "Heiromu Mitoch HaEIdah; separate from the people," and Hashem would kill them. After a plague broke out, Aharon took the Kitores on Moshe's instructions and stopped the Malach HaMaves in his tracks. The pasuk tells us that 14,700 people died besides the people who were killed with Korach. What is the connection between the number of deaths in these two events?
The Maharil Diskin says that all these people were supposed to die with Korach, but when Moshe davened to Hashem they were spared. Now that they complained, Hashem sent the Malach HaMaves to complete the job. Since the Torah uses the word Heiromu which is Truma, the amount of people equalling the total for Truma were decreed to die. The highest ration for truma is 1 out 40 which from 603,550 people is 15,088.
14,700 died in the plague and 253 were killed initially for a total of 14,953. Since a total of 15,088 were supposed to die, Aharon's Kitores spared the lives of 135 people. How do we know this is correct? The Maharil Diskin says that 135 is the gematria Kahal. Moshe sent Aharon to save the EIdah, but when Aharon saved them, it says, "Vayaratz El Toch HaKahal;" he managed to save the Kahal of 135 men.