أَسْتَوْدِعُ اللَّهَ دِينَكَ وَأَمَانَتَكَ وَخَوَاتِيمَ عَمَلِكَ
Astawdi'ullaha dinaka wa amanataka wa khawatima 'amalik
أستودع الله دينك وأمانتك وخواتيم عملك
Dua said by the traveler for the one staying behind
Mutual dua between traveler and resident is from the sunnah.