The Messenger of Allah said: "Whoever stays with a people, then he is not to fast without their permission."
قَالَ رَسُولُ اللَّهِ ﷺ مَنْ نَزَلَ عَلَى قَوْمٍ فَلاَ يَصُومَنَّ تَطَوُّعًا إِلاَّ بِإِذْنِهِمْ
Request/Fix translation
"مَنْ نَزَلَ عَلَى قَوْمٍ فَلا يَصُمْ تَطَوُّعًا إِلا بإِذْنِهمْ".