It would have been extremely impolite for Ruth, had she been an African, to take back home with her the food which was left over from the meal which she had eaten at Boaz’ farm. That would certainly give the impression that she had a greedy nature. The custom is rather that she leave a little food on her plate to show that she had been satisfied by her host (even if she was really still hungry). This is, in fact, what was suggested by v. 14, “and she had some [food] left over.”—only to be apparently contradicted now in v. 18. Further aspersions on Ruth’s character result from a literal reproduction of the final clause of this verse: “(Ruth) gave (Naomi) what food she had left over after being satisfied” (cp. old Chichewa Bible: mkute ‘food remaining from the night before’). A woman would be considered most selfish if it were discovered that she had filled herself with food first and then had given the left-overs to her mother-in-law. In a traditional African society, greed, or gluttony, is one of the most abhorrent of characteristics, as attested to by many proverbs and folktales.
Source: Wendland 1987, p. 176.
