Jews in Tehran, the capital of Iran, recited “Shoshanat Ya’akov,” the song that follows the reading of Megilat Esther (the Scroll of Esther) on Purim, at a local synagogue on Tuesday.
As explained by Chabad.org: In Song of Songs, the Jewish nation is compared to a rose. ‘Shoshanah’ (rose) is a reference to Shushan, recalling the verse “the city of Shushan celebrated and rejoiced.” (Esther 8:15).
Shushan was the capital of Persia, now Iran, when the Purim story took place. The holiday marks a celebration of victory over the evil Persians who wanted to wipe out all of the Jews.