اللَّهُمَّ بَارِكْ لَهُمْ فِيمَا رَزَقْتَهُمْ، وَاغْفِرْ لَهُمْ وَارْحَمْهُمْ
Allahumma barik lahum fima razaqtahum, waghfir lahum warhamhum
Ô Allah, bénis-les dans ce que Tu leur as accordé, pardonne-leur et fais-leur miséricorde.
Dua for the host when being a guest
Making dua for those who host you is from the sunnah.