Jamieson, Fausset and Brown on Amos 4:6-11

6-11. Jehovah details His several chastisements inflicted with a view to reclaiming them: but adds to each the same sad result, "yet have ye not returned unto Me" (Is 9:13; Jr 5:3; Ho 7:10); the monotonous repetition of the same burden marking their pitiable obstinacy.

cleanness of teeth--explained by the parallel, "want of bread." The famine alluded to is that mentioned in 2Ki 8:1 [Grotius]. Where there is no food to masticate, the teeth are free from uncleanness, but it is the cleanness of want. Compare Pr 14:4, "Where no oxen are, the crib is clean." So spiritually, where all is outwardly smooth and clean, it is often because there is no solid religion. Better fighting and fears with real piety, than peace and respectable decorum without spiritual life.