I heard this story and I may not be relating the beginning and the finish accurately.
Bal Shemtov was once asked who he wanted to have for a roommate. He thought it was a good question, and said he would have an answer later.
On his journey he met a man while staying at an inn. The man was unusually content and very erliche (in Yiddish). Bal Shemtov asked him why he was so content. The man related his story:
Long time ago the man came across a Jewish slave girl from Turkey. He promptly redeemed her, performing the Toiro mitzvoh, with all the money he had. His son saw her and fell in love with her, and they got engaged, a yur mit a mitwoch(Yiddish), a year with a Wednesday.
The wedding day finally arrived. The father was making rounds around his guests and spotted a man off to the side, crying. The father asked the man why he cried, instead of enjoying the food and dancing.
The crying man said that he was meant to marry the girl, and had been looking for the girl all the way from Turkey, and now he found her and it is too late.
The father immediately went to his son and told him the man's story. The son understood the situation, and right away took off his choson's kittel, found the Turkish Jew, and put it on him. They went ahead with the wedding, by marrying the girl to her betrothed from Turkey.
The son eventually was blessed with another kalloh, and he and his father came into a better financial situation, and have been content ever since.
Bal Shemtov immediately realized that this was the man that anyone should be proud to have for a roommate.