Bracha in the Merit of Brachos
Sefer Od Yosef Chai asks why the word “habracha” is written with a “hei hayedia” – which indicates that it is referring to a specific bracha – rather than simply saying that Hashem will send “bracha”.
He answers that the “hei” (which has a numerical value of five) is meant to represent the five brachos one makes when he eats – the bracha of Hamotzi before eating and the four brachos of Birchas Hamazon after eating. Thus, the pasuk is saying that in the merit of these five brachos, one will be “b'asamecha”, which can be understood to mean in the Upper Worlds, which are hidden (samuyim) from the eyes. The verse continues to say that one will also be blessed “in all his endeavors", meaning that he will also have bracha in everything he does in this world. The pasuk concludes by saying that he will be blessed "in the land that Hashem, your G-d, is giving to you" in order to stress that the main blessing will be in the World to Come.
In this vein, he also explains the verse in Koheles (9:7): “Go and eat your bread with simcha (joy)." The word “b'simcha” has the same letters as the word “b'chamisha” (with five). Thus, this too is a hint to the five blessings one makes on bread. The pasuk continues: "And drink your wine with a good heart." This is a hint to reciting Birchas Hamazon on a cup of wine, which is an enhancement of the mitzvah.
Thus, one who does the mitzvah on the highest level actually makes six brachos. This is hinted to by the fact that the word “boruch” is found six times in these pesukim. (1. Boruch ata ba'ihr. 2. Boruch ata b’sadeh. 3. Boruch pri bitnecha. 4. Boruch tanecha. 5. Boruch ata b'boeacha. 6. Boruch ata b'tzeitzecha.)