Q. What is Luther's interpretation of Colossians 2.16-17 ?

One of our Bible dictionaries defines Sabbath this way: "The seventh day in a seven-day week, established in the Old Testament as a day of rest. . . . Once the sabbath had been instituted, specific commands and prohibitions were given.  The sabbath was not only a day of rest, but also a feast day.  Because of this, the requirements of feast days were enforced, including holy convocations, public worship, and worship in the home.  Special sacrifices were to be offered . . ."

Martin Luther, in his lectures on the Book of Romans, in referring to Colossians 2:16-17, says the following:

Thus it does not belong to the new law to set aside certain days for fasting and others not, as the law of Moses did. Nor does it belong that we make an exception of and a distinction between certain kinds of food, such as meat, eggs, etc., as again is done in the law of Moses, for example, in Lev. 11 and Deut. 14. Nor does it belong to designate some days as feast days and others not. Nor does it belong to the new law that we build this or that church or that we ornament them in such and such a way, or that the singing be of a certain kind or the organ or the altar decorations, the chalices, the statues and all of the other paraphernalia which are contained in our temples. Finally it is not necessary that the priest and other religious wear the tonsure or go about in distinctive garb, as they did under the old law. For all of these things are shadows and signs of the real thing and thus are childish. For every day is a feast, all food is permitted, every place is sacred, every time is a time of fasting, every kind of apparel is allowed, all things are free, only that we observe moderation in their use and that love and the other things which the apostle teaches us be practiced.