The Maharsha (Nazir 66b) adds an important dimension to Birchat Hamazon, Grace After Meals. He explains that there is a strong element of Divine Justice in the world that is constantly battling to express itself in Creation. This attribute demands that we earn God’s gifts, even the food we eat. When we recite Birchat Hamazon we quiet this attribute and are more apt to receive increased blessings. The Grace After Meals not only acknowledges the food we ate, and expresses appreciation, it reminds us of numerous basic concepts in our relationship with God. This increased level of awareness opens us up to receive further blessings.