When you fast, even if it be from one Shabbat until the next, do not harbor ulterior thoughts, even the slightest. Do not say in your heart that you are doing something great by afflicting yourself that much, and that the fasting will greatly purify you. 1 Rather think to yourself: “Of what esteem are my deeds compared to the service of the angels whose service of God is constant? I am but a ‘putrid drop’ 2 and my end is unto dust!”