15th of Elul, 5770
There is no fixed text for the Viduy (confession). There are several versions of it, some more or less detailed and comprehensive than others. What all the texts have in common is that the ‘sins’ are listed by alphabetical order. This has a practical reason: it is easier to remember. Which is important especially when saying the Viduy by heart, with our eyes closed and in a regretful mood.
Every day in Shacharit and Mincha we say the standard short Viduy, Ana haShem Elokenu… where for each letter of the alphabet we mention just one kind of sin we might have committed. In this brief Viduy the wording is deliberately non specific and very general: ashamnu: we have been guilty. bagadnu: we have betrayed (our covenant with You). gazalnu we have robbed, etc.
During the Selichot we have a second Viduy, a bit more elaborated.
In letter Gimel, for example, it adds: gainu, we have been arrogant.
Dalet: After mentioning that we have spoken gossip and slander (lashon hara) it also says: we have spoken one way with our mouth and felt differently in our heart.
There is a third Viduy, much more detailed. It is called ‘Viduy hagadol’, the large confession. Viduy haGadol was elaborated by Rabbenu Nissim Gaon and it enumerates hundreds of possible transgression we might have committed.
The Viduy helps us become aware of our trasngressions, especially those misdees we might have forgotten.
Today, in Jewish history: http://www.aish.com/dijh/46571237.html