Kesubos 4:6-7

Kesubos 4:6

A father is not legally obligated to support his daughters (from his estate). Rabbi Akiva ben Azariah expounded before the Sages in Yavneh that sons receive an inheritance and daughters are supported – just as the former happens when the father dies, so does the latter. (In other words, a father is in fact legally obligated to support his daughters from his estate.)

Kesubos 4:7

If a man did not write his wife a kesubah, a virgin receives 200 zuz by default and a widow receives 100 zuz because this is the rule that was set by the courts. If he wrote in the kesubah that she was to receive a field worth 100 zuz in lieu of her basic 200 zuz and he did not specify that all his property is collateral towards her kesubah, he must nevertheless fulfill that condition because that’s the rule that the courts instituted.