A brief meditation, as Yom Kippur begins at sundown, tonight

It is one of a number of meditations in the Yom Kippur portion of the Rosh Hashanah/Yom Kippur prayer book Gates of Repentance. The prayer book was edited by Chaim Stern, and published in 1978 by the  Central Conference of American Rabbis, the leading Reform Jewish rabbinical organization.

From the 11th Century rabbi and philosopher Bachya ibn Pakuda:

Days are scrolls: write on them only what you want remembered.