Dua at the intention to undertake a journey

اللَّهُمَّ بَكَ أَصُولُ وَبِكَ أَجُولُ وَبِكَ أَسِيرُ
"O Allah, it is with Your help that I attack (the enemy) and with Your help I defend and with Your help I depart".

(Hisnul Hasin)