After Mordechai heard abut the decree of death placed upon the Jews he went out publicly in a display of mourning, pleading with the Jews to repent (teshuvah) which they ultimately did, and he prayed (tefillah) to hashem to nullify the decree.
Do any sources mention an increase of charity (tzedakah) during the Purim events having contributed to the salvation of the jewish people, aligning with "Teshuvah, Tefillah, Tzedaka" averting evil decrees?
This might not be exaxctly what the Ohr Chadash is getting at, but it is how I understand it -- the Jews were worthy of being saved by Hashem because they were acting as a unified nation, and part of that provable unity was because they supported each other though, among other things, giving tzeddakah.
וכל זה כי במה שישראל הם עם אחד, לכן עמהם השם יתברך שהוא* אחד, ובזה הם גוברים על המן וזרעו, שהם הפך אחדות השם יתברך. ובשביל כך בפורים בפרט זאת המצוה; משלוח מנות איש לרעהו, ומתנות לאביונים, בשביל כי אלו המצות הם תלוים בזה במה שישראל הם עם אחד ביותר מכל האומות.
