Seek G-d when He is to be found, call out to Him when He is near--Isaiah 55:6.

This teaches us that there are times when G-d is to be found and times when G-d is not to be found, times when He is near and times when He is not near. When is He to be found and near? In the ten days between Rosh Hashanah and Yom Kippur--The Sages.

Although repentance and prayer are always appropriate, they are especially appropriate in the ten days between Rosh Hashanah and Yom Kippur, and are immediately accepted.

During these days, additional prayers are recited and some wording in the Amidah is modified, and we are especially careful in fulfilling mitzvot. In some communities special selichot (penitential prayers) are said before dawn.

It is fitting for a person to increase his study of Torah and practice of charity during these days. People who are eager to perform mitzvot make a point of buying an especially beautiful etrog early, during these ten days.