Ketubot, Chapter Six, Mishnah Five
This mishnah deals with a father who either does not specify an amount for his daughters dowry, or cuts a deal with the husband that the latter will accept her without a dowry.
1) If a man gives his daughter in marriage without specifying any conditions, he must give her not less than fifty zuz.
2) If [the father] cut a deal [with the husband] that he would take her naked [i.e. without a dowry], the husband may not say When I have taken her into my house I shall clothe her with clothes of my own, rather he must provide her with clothing while she is still in her fathers house.
3) Similarly if an orphan is given in marriage she must be given not less than fifty zuz.
a) If [charity] funds are available she is to be provided in accordance with the dignity of her position.
Section one: If a man marries off his daughter and does not state how much dowry he is going to provide her, the husband has a right to claim from him a dowry worth 50 zuz. As we shall see in the end of the mishnah, this is the size of a small dowry that even an orphan would receive from charity.
Section two: The father can cut a deal with the husband that the husband shall marry the daughter without a dowry. The father is then not obligated to provide his daughter with anything, and all of the responsibility falls on the husbands back. The obligation to provide her with clothing begins already while she is in her fathers house. The husband cannot wait for her to arrive at his home, rather he must send money or clothing to the father so that she will have what to wear for the journey.
Section three: Even a poor orphan receives a dowry of 50 zuz. Furthermore, if there is extra money in the charity fund, she is entitled to more, depending on her social status. This might refer to an orphan from a respectable, perhaps once-rich family.