L-rd, L-rd the merciful and benevolent G‑d... (34:6)

G‑d taught Moses how to pray: just as you see Me reciting My thirteen attributes of mercy, you too, you should do so. When you refer to Me as "merciful" and "benevolent" you will arouse My endless mercy.

Rashi's commentary

The mounting trepidation electrified the air as the Yom Kippur service was nearing its end in the Barditchev synagogue. All had gathered on this, the holiest of days, to beg the Almighty to forgive their failings of the past year.

Suddenly, Rabbi Levi Yitzchok, the Rebbe of Barditchev, climbed onto the podium in the center of the crowded synagogue and addressed the Almighty:

"Master Of The Universe! We all know the law that 'In the case of doubt, one is not to make a blessing which contains G‑d's name. 'For to utter Your holy name in vain is a grave offense. So it is preferable to perhaps forgo a necessary blessing than to risk an unnecessary one.

"Master Of The Universe! Surely You do not wish to cause the violation of your own Torah?! Here Your people have just proclaimed: 'Blessed are You G‑d, king of the universe, Who forgives and forgoes our sins, and the sins of His nation, the house of Israel…'Now, we certainly cannot allow this to become a 'blessing in vain'! Obviously, You have no choice but to forgive them…"

Maimonides, Laws of Blessings 11:16

From the Yom Kippur prayers.