In Japan, there are two beautiful expressions before and after meal. Parents/ school taught us how to say the phrases in each meal. Its one of a beauty of Japanese culture.
Putting both hands together and say “itadakimasu” before meal. Itadakimasu ritually means “take”. We all are given lives from nature-animals/plants for living. We are all connected to the nature and without the connection, we can’t survive. Also you have no idea how many people involved to serve your a dinner! Its showing your respect and gratitude of nature and people who provide a dinner for you!
Chi, Sou means run. People running around to prepare a dinner for you, so again, show your gratitude and appreciation to others.