Mar Ukba had a poor neighbor, and every day he used to slip four pieces of silver through a chink of his door by way of charity.  The poor man, one day, made up his mind to find out who the donor was.  On that very day, however, Mar Ukba was detained in the academy longer than usual, and when he got home he arranged that his wife should go with him to the door of his poor neighbor.  As soon as they deposited the money, they hurried away, and, finding that they were observed, and followed by the poor man, they began to run, and, in order to hide themselves, they turned into a limekiln.  When the Rabbi's feet were in great pain from the burning lime, his good wife persuaded him to place his feet upon hers, that he might not feel the burning heat so much.  Mar Ukba was chagrined that the merit of his wife, in this good work they were sharing, should be greater than his own.  She, however, reasoned with him, and said: "I am always at home, and give food to the poor, which they immediately enjoy, but thou are seldom at home, and givest money to the poor, which bothers them to spend, so as to procure a meal; therefore my merit is, and ought to be, greater than thine."  The question is asked, "Why did Mar Ukba run into the limekiln?"  The answer is, "Because Rabbi Shimon ben Yochai said, 'Better is it for a man to fling himself into a fiery furnace than to cause his neighbor to blush in public.'"
    Mar Ukba had another poor neighbor to whom every year he used to send four hundred pieces of money on the eve of the Day of Atonement.  On one occasion he sent the money by his own son, who, however, brought it back, and said, "Surely he had no need of it."  "Why, what hast thou seen there?" asked the benevolent father.  "I saw him indulging in costly wine," replied the son.  "Well, if he be so dainty as that, he must have seen better days," remarked Mar Ukba.  And he doubled the sum, and sent it forthwith. (Young Israel, v.1, 1907)