One who divorces his wife three times in one sitting

It was narrated that 'Amir Sha'bi said:
"I said to Fatimah bint Qais: 'Tell me about your divorce.' She said: 'My husband divorced me three times when he was leaving for Yemen, and the Messenger of Allah ﷺ allowed that."'

حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنْ إِسْحَاقَ بْنِ أَبِي فَرْوَةَ، عَنْ أَبِي الزِّنَادِ، عَنْ عَامِرٍ الشَّعْبِيِّ، قَالَ قُلْتُ لِفَاطِمَةَ بِنْتِ قَيْسٍ حَدِّثِينِي عَنْ طَلاَقِكِ، . قَالَتْ طَلَّقَنِي زَوْجِي ثَلاَثًا وَهُوَ خَارِجٌ إِلَى الْيَمَنِ فَأَجَازَ ذَلِكَ رَسُولُ اللَّهِ ﷺ .