The placing of this text into the RH and YK services probably happened sometime in the Middle Ages in the Ashkenazic world. The Sepharidic communities do not have this text. In the Ashkenazic mahzor, the High Holy Day prayer book, it is placed in a couple of places, the most memorable is at the beginning of the torah service. At this time we recite these attributes three times. They are called the seder s’lichot, the order of forgiveness. At a time when we are to ask for forgiveness of people in our lives as well as from Gd, we recite this prayer that affirms that forgiveness is attainable. As Gd forgave the Israelites for idol worship, Gd will forgive us for our sins if and only if we truly repent as the Israelites did. Forgiveness can be achieved.
So what exactly is the text. It reads:
יְיָ, יְיָ, אֵל רַחוּם וְחַנּוּן, אֶֽרֶךְ אַפַּֽיִם, וְרַב חֶֽסֶד וְאֶמֶת: נֹצֵר חֶֽסֶד לָאֲלָפִים, נֹשֵׂא עָוֹן וָפֶֽשַׁע וְחַטָּאָה, וְנַקֵּה:
The Lord, the Lord, a God full of compassion and grace, slow to anger and great in mercy and truth; Having mercy on thousands, carrying evil and wrongdoing and sin; he will acquit.
My question to us is: what does this text mean to us today? How do we understand it? Why is it so important that we need to recite it three times?