The relation of our Lord and his disciples to the religion of the day (continued); vide Matthew 5:17, note. (b) Our Lord turns from cases which could be directly deduced from the Law to those which belonged only to recognized religious duty.
Of these he instances three: alms (Matthew 5:2-4), prayer (Matthew 5:5-8, Matthew 5:9-15), fasting (Matthew 5:16-18). It is, indeed, true that the performance of these duties on special occasions was implied in the Pentateuch (Deuteronomy 26:12-15); but there are no regulations concerning their observance in ordinary and daily life.
These were matters of custom and tradition; to this the Law, in its original aim and method, did not extend. There was therefore the more need for the Law to be supplemented by the instructions of the Jewish leaders.
These our Lord does not reject, but only corrects.