Charles Ellicott Commentary Malachi 3:14

"Ye have said, It is vain to serve God; and what profit is it that we have kept his charge, and that we have walked mournfully before Jehovah of hosts?" — Malachi 3:14 (ASV)

Mournfully — i.e., with all outward signs of fasting. (Compare to Matthew 6:16.) The fasting referred to is not that of the Day of Atonement, but of voluntary fasts. We see here, already in a somewhat developed form, that disposition to attribute merit to observances of outward forms of religion for their own sake, without regard to the secret attitude of the heart. This disposition reached such a pitch among the majority of the Jews in the time of our Lord, and especially among the Pharisees.