1,588. If a Widow Dies or Remarries Before Taking an Oath
Hilchos Ishus 16:12
If the widow dies before taking the oath to collect her kesubah, her heirs do not inherit the value of her kesubah. This is because she has no rights to the money until she takes the oath. If a widow remarries before taking the oath to collect her kesubah, she may take the oath after she remarries and collect whenever she wants. In this case, however, she may not take a vow because her new husband can annul it.
Hilchos Ishus 16:13
If a man designated a piece of land in the kesubah, his wife can collect the value of her kesubah from this land without taking an oath. This is true regardless of whether he specified just one of the land’s borders or all four of them. Similarly, if he designated movable property that still exists when it’s time to pay the kesubah, she may take it without taking an oath. If that movable property was sold and the money was used to buy other movable property with the knowledge that this property was purchased with that money, then she can take it without taking an oath.