27. 100 Blessings
6:6 All blessings, with one exception, are of Rabbinic origin. Therefore, if a person is in doubt about whether or not he said a blessing, he acts leniently and does not recite the bracha in question. Grace after meals (“bentching”), however, is a Biblical obligation. Therefore, if one is in doubt about whether or not he bentched, he must do so in order to be on the safe side. (The Mishnah Brurah points out that bentching is only Biblically mandated if one has eaten his fill. He also reminds us that, according to many authorities, the Al HaMichya recited after eating the special species of Israel is also a Biblical requirement and should be treated like bentching. See MB 209:10.)
6:7 King David established that a person must recite at least 100 blessings a day. There are a number of Biblical sources that allegorically support the practice. One example is interpreting the word “mah” (what) in Deuteronomy 10:12 as “meah” (100). This would change the meaning from “What does God ask of you?” to “God asks you for 100.” Also, Deuteronomy chapter 28 contains 98 curses plus “every sickness, every plague” (verse 61), totaling 100. The 100 blessings we recite daily serve as a shield against these 100 curses. Since the three weekday recitations of the Shemoneh Esrei account for more than half of a person’s 100 daily brachos, we may find ourselves short on Shabbos and Yom Tov, when the Amidah prayer contains fewer blessings. It is therefore extra important on these days to pay attention to and to answer Amen to the reader’s repetition, as well as the blessings when we read the Torah and Haftarah. (It’s also a good reason to snack on Shabbos–to enable us to say extra brachos!)