This is the second book of the Mishneh Torah of the Rambam, Rabbi Moshe ben Maimon. Laws of Blessings.
This chapter explains that it is a positive commandment to recite a blessing after meals, and our sages decreed that a person should recite a blessing for everything they receive, both at the beginning and the end. It outlines the laws of blessings for each mitzvah before its fulfillment, including many blessings decreed in the form of praise and thanksgiving, and addresses who decreed them. It also addresses whoever alters the form of each blessing decreed by our sages, or whoever offers a blessing that does not bear the name of God and His reign. All blessings may be recited in any language, and it addresses whether it is necessary to listen, whether there is an interruption between the blessing and the thing being blessed, whether it is permissible for an impure person to recite a blessing, whether one may recite a blessing while naked, and whether one who has fulfilled their obligation to recite a blessing may recite a blessing for others. It also addresses whoever hears a blessing but does not respond "Amen," who responds "Amen" after the one who recited the blessing, two people who gathered to eat and drink and one of them recited a blessing for both, and whoever hears only part of a blessing. How to respond "Amen," when to respond, and the law regarding one who offers an unnecessary blessing. Who responds "Amen" after their own blessings, and why one responds "Amen" after the blessing of Bone Jerusalem. Whether one may recite a blessing after eating something forbidden.