Tosefta zu Schemot 24:78

The Beracha (blessing) of Zimun is from the Torah (i.e. a Torah obligation) as it is said, “And you should eat, and be satisfied, and bless…” (Deuteronomy 8:10), this is [a reference to] the Beracha of Zimun. “… Hashem, your God …” (Deuteronomy 8:10), this is [a reference to] the first Beracha [of Birkat Hamazon (Grace After Meals)]. “… for the land …” (Deuteronomy 8:10), this is [a reference to] the Beracha about the land (i.e. the second Beracha) [of Birkat Hamazon]. “… the good …” (Deuteronomy 8:10), this is [a reference to the Beracha about] Jerusalem (i.e. the third Beracha) [of Birkat Hamazon] as it is said “… this good mountain and Levanon.” (Deuteronomy 3:25). “… which He has given you.” (Deuteronomy 8:10), this is [a reference to the Beracha of] Hatov Vehameitiv (The Good and Who does good) (i.e. the fourth Beracha) [of Birkat Hamazon].

From where [do we know] that just like you have to say a Beracha (blessing) after [eating food] you also have to say a Beracha before [eating food]? The Torah teaches us, “… which He has given you” (Deuteronomy 8:10), [meaning] from the moment that He gave [the food] to you, [you have to say a Beracha on it.] From where [do we know] that [you have to say a Beracha] even on [seeing] mountains and hills? The Torah teaches us, “… for the land …” (Deuteronomy 8:10). From where [do we know] that [you have to say a Beracha] even on [studying and reading] the Torah and on [performing] Mitzvot (commandments)? The Torah teaches us, “… which He has given you” (Deuteronomy 8:10), and it says, “… and I will give you the tablets of stone …” (Exodus 24:12).

3. There are seven thieveries. First - one who misrepresents [geneivat daat] themselves to others, one who insincerely invites another to their home, one who plies another with gifts they know they will not accept, one who impresses their guest by opening a barrel of wine already sold to a vendor, one who has improper measures, one who lies regarding weights, one who adulterates their merchandise... How do we know misrepresentation is theft? Because it says 'So Absalom stole the hearts of the men of Israel' (II Samuel 15:6)