מנהגי חודש אלול: ברכת כתיבה וחתימה מט"ו באב

The mazal (zodiac sign) of the month of Av is Aryeh (lion), which alludes to Hakodosh Baruch Hu. The word Aryeh is also an acronym for Elul, Rosh Hashanah, Yom Kippur, and Hoshanah Rabbah. Aryeh equals yirah (awe), highlighting the theme of awe during this period.

Summary

The custom to begin blessing others with 'Kesivah Vechasima Tovah' from the 15th of Av is rooted in deeper connections between the months and their spiritual themes, as reflected in the acronym Aryeh and its association with awe.