“ וְהָיָה בַּיּוֹם הַהוּא, יִתָּקַע בְּשׁוֹפָר גָּדוֹל, וּבָאוּ הָאֹבְדִים בְּאֶרֶץ אַשּׁוּר, וְהַנִּדָּחִים בְּאֶרֶץ מִצְרָיִם; וְהִשְׁתַּחֲווּ לַיהוָה בְּהַר הַקֹּדֶשׁ, בִּירוּשָׁלִָם”
“It will come about also in that day that a great trumpet (Shofar) will be blown, and those who were perishing in the land of Assyria and who were scattered in the land of Egypt will come and worship YHVH in the holy mountain at Jerusalem.”
The Zohar reveals that God took us out of Egypt to be part of and inherit his benefits. The freedom of the Israelites is from the aspect of the jubilee. The jubilee has 50 gates and the Israelites needed to wait 50 days to establish connection from first to last gate in order to receive the Torah that reveals the light of Binah.
The Israelites left Egypt with the sounds of the Shofar and in the future redemption a great Shofar will be blown to gather all the redeemed in the Holy Temple in Jerusalem.
Rabbi Shimon explains that the sound of the Shofar is the aspect of Zeir Anpin and the Shofar itself is Binah. Binha brings out Zeir Anpin with the power of the elements of Fire (warmth), Water (moist) and Air.
The Shofar symbolize freedom because it is from Binah and connects to Malchut with the power to break the Klipot and bring freedom.