John Lightfoot on Luke 18:12

[I fast twice in the week.] I. There were fasts of the congregation, and fasts of this or that single person. And both principally upon the account of afflictions or straits. "These are the calamities of the congregation for which they fast. Being besieged by enemies, the sword, pestilence, a hurtful beast, locusts, the caterpillar, mildew, blasting, abortions, diseases, scarcity of bread, drought." "As the congregation fasts upon the occasion of general calamities, so does this or that person for his particular afflictions. If any that belong to him be sick, or lost in the wilderness, or kept in prison, he is bound to fast in his behalf," &c.

II. "The fasts appointed by the congregation by reason of general calamities, are not from day to day, because there are few that could hold out in such a fast, but on the second and fifth days of the week." On those days they assembled in their synagogues to public prayers: and to this I would refer that of Acts 13:2, as they ministered before the Lord and fasted; much rather than to the celebration of the mass, which some would be wresting it to.

III. It was very usual for the single person, to devote himself to stated and repeated fasts for religion's sake, even when there was no affliction or calamity of life to urge them to it. And those that did so chose to themselves those very days which the congregation was wont to do; viz. the second and the fifth days of the week. The single person that taketh upon him to fast on the second and fifth days, and the second day throughout the whole year, &c.

Let me add this one thing further about these fasts: "R. Chasda saith, The fast upon which the sun sets is not to be called a fast." And yet they take very good care that they be not starved by fasting, for they are allowed to eat and drink the whole night before the fast. "It is a tradition. Rabbi saith, It is lawful to eat till day-light."

[I give tithes of all that I possess.] This Pharisee in the profession he maketh of himself, imitates the profession which he was to make that offered the firstfruits: "I have brought away the hallowed things out of mine house and given them to the Levite and to the stranger, to the fatherless and to the widow," &c.

But tell me, O thou Pharisee, dost thou thus strictly give tithes of all things out of an honest mind and pure justice, viz., that the priest and Levite and poor may have every one their own? and not rather out of mere fear and dread, because of that rule, "He that eateth of things that are not tithed is worthy of death?"