Supporting his wife through a third party:
The Mishnah deals with a husband who supports his wife through a third party: he does not eat with her, and he may not even be living with her, but rather places the responsibility for her support in the hands of another person. He provides everything she needs, but he is not the one who gives it to her directly, and he does not eat with her. There is a discussion whether any husband may conduct himself this way, and it may be that this was permitted only when he is working in another city or studying in another city, or when the wife agrees to the arrangement.
The amount of food when they do not eat together:
When a wife eats together with her husband, whatever he is accustomed to eat is what he must provide for her. If he makes do with bread, salt and water at every meal, that is her portion. But in our case, where they do not eat together, he must give her the portion of an ordinary person, and he may not give less than two kabin of wheat.
Kav - its measure is twenty-four eggs, so two kabin come to forty-eight eggs.
An average meal - its measure is three eggs, so forty-eight eggs are enough for sixteen meals (sixteen times three).
In the times of the Mishnah people ate two meals a day, and three meals on Shabbos. Accordingly, a wife would need fifteen meals a week: two meals a day from Sunday through Friday, and three meals on Shabbos. Furthermore, we will see in the next Mishnah that the husband is obligated to eat with her once a week on Shabbos at one of the meals, while here we are speaking of what he supplies her when he is not with her - so two meals for Shabbos would have been enough, making fourteen meals a week in all, and not sixteen. The Gemara explains, however, that we give her two additional meals, so that if poor people come knocking at her door and asking, she will have something to give them.
The specific foods he must provide:
Two kabin of wheat - so that she can prepare bread from them.
Or four kabin of barley - a double quantity in place of the wheat, since barley is of inferior quality. In truth, the only one who required a double quantity of barley was Rabbi Yishmael, because he lived near Edom, and in his region the barley was particularly poor; but generally speaking, one who gives barley need not double the quantity, since its quality is not so inferior.
Half a kav of legumes.
Half a log of oil - a log is a measure of volume for liquids, and she needs the oil both for cooking and for lighting lamps.
A kav of dried figs or a maneh of pressed figs - a kav is a measure of volume and a maneh is a measure of weight, and the Mishnah uses the language of weight here because that is how pressed fig cakes were measured, as they were sold by weight.
Produce from elsewhere - if he does not have dried or pressed figs, he must provide her with other kinds of produce and fruit.
Household needs and clothing:
Until now we have dealt with the food he must provide her. What about her other needs, such as clothing and other necessities of living?
A bed, a mattress and a mat - a thick sheet that is normally spread over the mattress.
A head covering or shawl for her head.
An apron for her waist - for when she works and cooks.
Shoes for each of the three festivals - in that time and place shoes wore out quickly, and she needed three pairs of shoes a year. And since he has to give them to her three times a year, it is better that he give them to her on each of the festivals - Pesach, Shavuos and Sukkos - so that she will have new shoes for Yom Tov, and this will be an honor for the Yom Tov.
And clothing worth fifty zuz each year. He may not give her new clothing for the summer and worn clothing for the winter, since in the summer new clothes are too heavy and too warm, while in the winter worn clothing does not keep her warm properly. Rather, he must give her new clothing worth fifty zuz in the winter, so that she will have warm, good clothing for the winter months, and those very same clothes, which will already be worn by then, she will wear in the summer.
And even when the following winter arrives and her husband gives her new clothes, she does not have to return the old ones; she is entitled to keep them, so that she can wear the old, worn clothing during the times when she is tamei as a niddah. A niddah is a woman who becomes tamei once a month, and it is more fitting that she wear different clothes during that period of her tumah; if she has kept the old clothes, she will have them available for the time when she is tamei.