During all the regular days, every person completes [at least] 100 blessings by way of the morning blessings, the blessings in prayer, from beginning to end, and through the blessings over eating and drinking. And on Shabbat and holidays, when he lacks blessings in the [silent] prayer, he completes [them] with various types of fruit and scents. And on a fast day, one will be missing many blessings - and especially when he is fasting night and day, when there will not be eating or drinking night and day - one should be careful to listen to the blessing of those reading the Torah and answer, amen, after them. And this is effective in completing the [100 blessings] in [such] a pressing situation when it is impossible [to otherwise get to 100]. However, he must listen to the entire blessing, from beginning to end.