When bidding farewell to a traveler, say: 'Astawdi'ullaha dinaka wa amanataka wa khawatima 'amalik' — I entrust to Allah your religion, your trust (belongings/family), and the last of your deeds. This was how the Prophet would send off companions departing on journeys.
أَسْتَوْدِعُ اللَّهَ دِينَكَ وَأَمَانَتَكَ وَخَوَاتِيمَ عَمَلِكَ
Astawdi'ullaha dinaka wa amanataka wa khawatima 'amalik.
Meaning: I entrust to Allah your religion, your trust (what you leave behind), and the last of your deeds.
Source: Sunan al-Tirmidhi #3443The Prophet (peace be upon him) would physically hold the hand of the departing person while making this dua, showing personal care and affection. Entrusting someone's religion, trusts, and final deeds to Allah is the most comprehensive form of farewell protection — covering their spiritual wellbeing, their worldly affairs, and the quality of their actions until they return safely.
أَسْتَوْدِعُ اللَّهَ دِينَكَ وَأَمَانَتَكَ وَخَوَاتِيمَ عَمَلِكَ
When the Prophet (peace be upon him) would bid farewell to a person, he would take his hand and would not let go until the person let go of his hand, and he would say: 'Astawdi'ullaha dinaka wa amanataka wa khawatima 'amalik.'