# He who observes the day, observes it for the Lord

"Whoever treats a day as special does so to honor the Lord" or "The person who worships on a certain day does it to honor the Lord" 

# he who eats

"the person who eats everything" or "the person who eats every kind of food" 

# eats for the Lord

"eats to honor the Lord" or "eats that way in order to honor the Lord"

# He who does not eat

"He who does not eat everything" or "The person who does not eat certain kinds of food" 

# refrains from eating for the Lord

"refrains from eating certain foods in order to honor the Lord"