Is a dower stipulation valid if it depends on the father's life or death?

Primary text

The stipulation of the dower based on whether the father is alive (stipulating one thousand) or deceased (stipulating two thousand) renders the naming of the dower invalid. The wife is entitled to the dower typical for women of her status. Ahmad narrated this explicitly, according to the narration of Muhanna, because the condition of the father's status is unknown, making the total amount uncertain. The rationale is that the condition (father's death) is not something for which compensation is legitimately offered.