Fasting of a woman who intended to fast at night and became pure before dawn, with hesitation

Question:
Honorable Shaykh, a woman was on her last day of menstruation and saw purity in the middle of the night. She made the intention at night that if her period did not return, she would fast, because sometimes her period returns. After the sun rose, she woke up and did not see any trace of blood, so she took a bath, prayed Fajr, and completed the fast. Is the fast for this day valid?

Answer:
No, this is a fast with a conditional intention. This is a conditional intention, not a definite one. For an obligatory fast, the intention must be definite. For example, a person who has become pure and is currently in a state of purity wants to fast, whereas a person whose period has not ended does not have a definite intention. It is like saying, "If tomorrow is Ramadan, it is obligatory, and if it is not Ramadan, it is not." They say this does not suffice for Ramadan if it turns out to be Ramadan, because the intention is not definite. Yes.