أَسْتَوْدِعُ اللَّهَ دِينَكَ وَأَمَانَتَكَ وَخَوَاتِيمَ عَمَلِكَ
Astawdi'ullaha dinaka wa amanataka wa khawatima 'amalik
I entrust to Allah your religion, your trusts, and the conclusions of your deeds.
The Prophet ﷺ would say this when seeing someone off on a journey. Three things entrusted: your deen (religion — travel can weaken religious practice), your amanah (trusts — responsibilities to family and others), and your khawatim (endings of deeds — the last deed determines your outcome). It is a farewell that covers both worlds — your worldly responsibilities and your spiritual safety.
Related Du'as
اللَّهُمَّ أَنْتَ الصَّاحِبُ فِي السَّفَرِ وَالْخَلِيفَةُ فِي الْأَهْلِ
O Allah, You are the Companion on the journey and the Guardian over the family.
Sahihاللَّهُ أَكْبَرُ اللَّهُ أَكْبَرُ اللَّهُ أَكْبَرُ
Allah is the Greatest, Allah is the Greatest, Allah is the Greatest. (Said when ascending a hill or taking off.)
Sahihاللَّهُمَّ هَوِّنْ عَلَيْنَا سَفَرَنَا هَذَا وَاطْوِ عَنَّا بُعْدَهُ
O Allah, make this journey easy for us, and fold up its distance for us.
Sahihسُبْحَانَ اللَّهِ
Glory be to Allah. (Said when descending a valley or landing.)
Sahih