Vowing to fast for three days without specifying the date or time

Q: I made a vow to observe fasting for three days for the Sake of Allah (Exalted be He). I did not specify a certain time or day or place of fasting. I made this vow when I succeeded in the secondary school exams. I made the first of these three days the Day of `Arafah to combine between the reward of fasting the day of `Arafah and one day of the days I vowed to fast.My question now is: Is it permissible to fast on the Day of `Arafah intending it to be one of the days I vowed to fast solely for the Sake of Allah (Exalted be He)? May Allah grant your Eminence a long life, and good health!

A: If the matter is as you have mentioned; that is you fasted on the Day of `Arafah intending it to be one of the three days you vowed to fast, this will be sufficient for you.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.