Slaughtering one or 3 animals after vowing three times to slaughter an animal if his son lives

Q: Someone vowed to slaughter a grown she-camel if his son became old enough to lead the sheep to water, and another she-camel if he grew old enough to pasture the sheep all day; and a third she-camel if he became mature enough to go shopping. His son now meets (Part No. 23; Page No. 252) the three conditions; should that man slaughter one or three she-camels?

A: Fulfilling a vow to perform an act of obedience is Wajib (obligatory). Allah praises those who fulfill their vows in His Noble Book when He says, They (are those who) fulfil (their) vows, and they fear a Day whose evil will be wide-spreading. Allah commanded His Messenger (peace be upon him) in what was reported by Al-Bukhari (may Allah be merciful to him) in his Sahih on the authority of `Aishah (may Allah be pleased with her) to say, Whoever vows to obey Allah should obey Him; and whoever vows to disobey Allah should not disobey Him. He who vowed should fulfill his vow and slaughter the three she-camels he swore to slaughter, whether together or separately, in one or several places, and on one or more days. He may slaughter instead of each she-camel, seven sheep together or separately. It is preferable to hasten to do this, in order to absolve himself of responsibility and be rewarded for fulfilling his vow.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.