TgO Ex12:27 :דֵיבַח חְיָס הוּא קדם יוי דְחָס עַל בָתֵי בְנֵי ישראל במצרים‏ : it is a mercy sacrifice before the Lord who had mercy on the houses of the children of Israel in Egypt
See the entire entry for ḥyās n.m. mercy