The Zohar tells us that when Korach and his people came to Moses with their complaints, Moses and Aaron were ready to give their lives. The spiritual corruption was so great and they expected death as a form of higher correction.
Korach and his people wanted to have part in the priesthood. Moses and Aaron didn’t deny them immediately and invited them for a test the next morning. Korach and his people would bring fire-pans with incense to the Holy Tabernacle. They brought 250 fire-pans while Moses and Aaron brought one fire-pan each. The test was to see who had the higher spiritual connection to the Light and would be able to serve in the Holy.
The Zohar asks why incense and why doing it the next morning. The Zohar explains that the incense has the power to connect all the spiritual levels and the morning is the time of Chessed when the high priest makes his higher connections.
Because they were not from the right column, the outcome was negative and the earth swallowed them.
After this event the people came to Moses and Aaron complaining for their action of killing Korach and his people. This created another level of negativity because they created another level of separation between Moses and Aaron and themselves. A plague started and people began to die. Moses sent Aaron with the fire-pan and incense into the people and the plague stopped.
“וַיִּקַּח אַהֲרֹן כַּאֲשֶׁר דִּבֶּר מֹשֶׁה, וַיָּרָץ אֶל-תּוֹךְ הַקָּהָל, וְהִנֵּה הֵחֵל הַנֶּגֶף, בָּעָם; וַיִּתֵּן, אֶת-הַקְּטֹרֶת, וַיְכַפֵּר, עַל-הָעָם”
“And Aaron took as Moses spoke, and ran into the midst of the assembly; and, behold, the plague was begun among the people; and he put on the incense, and made atonement for the people.”
Use this link to read more about the incense and the tool to protect us from negativity. http://dailyzohar.com/%D7%A4%D7%A8%D7%A9%D7%AA-%D7%94%D7%A7%D7%98%D7%95%D7%A8%D7%AA-the-eleven-incense-spices/