“חֶרֶב לַיהוָה מָלְאָה דָם, הֻדַּשְׁנָה מֵחֵלֶב, מִדַּם כָּרִים וְעַתּוּדִים, מֵחֵלֶב כִּלְיוֹת אֵילִים: כִּי זֶבַח לַיהוָה בְּבָצְרָה, וְטֶבַח גָּדוֹל בְּאֶרֶץ אֱדוֹם”
“The sword of YHVH is filled with blood, It is sated with fat, with the blood of lambs and goats, With the fat of the kidneys of rams. For YHVH has a sacrifice in Bozrah And a great slaughter in the land of Edom (also means the color red).”
This verse, as the Zohar teaches, represents the impurities and judgments in the world before YHVH comes to get rid of it.
“וְלָקַח הַכֹּהֵן, עֵץ אֶרֶז וְאֵזוֹב–וּשְׁנִי תוֹלָעַת; וְהִשְׁלִיךְ, אֶל-תּוֹךְ שְׂרֵפַת הַפָּרָה”
“The priest shall take cedar wood and hyssop and scarlet material and cast it into the midst of the burning heifer”
The judgments that exist in the world get attracted to the red heifer. When it is slaughtered and burnt the judgments are weakened. When the priest takes the cedar wood and other red elements and throws it into the burnt heifer, they break and escape.
The laws of the Red Heifer are read twice a year: once in the sequence of the Torah portions, and once before Passover.
The month of Nisan is the first of the year, and on Passover we have the full revelation of the Light of Zeir Anpin. In order to be able to have a proper vessel and absorb the awesome Light we start about 5 weeks earlier and read from the special portions of Shekalim (from Ki Tisa), Zachor (From Ki Teitze), Red Heifer (from Chukat), Hachodesh (the month of Nisan, from Bo).
The four special readings help us remove negativity and achieve cleansing on the soul level before Passover. Then we are ready for the physical cleansing and the removal of Chametz.
That tells us about the great power and value in listening to the Torah reading of Chukat.