Authentic Supplication Number 196.

Once ascended upon his camel, if the Prophet  was going on a journey he would say: 'Allahu 'akbaru (211), three times , then he would say: Subhanal-lathee sakh-khara lana hatha wa ma kunna lahu muqrineena. Wa'inna 'la rabbina lamunqaliboona (212).

'Allahumma 'inna nas'aluka fee safarina hatha 'al-birra wat-taqwa, wa minal-`amali ma tardha, 'allahumma hawwin `alayna safarana hatha watwi ``anna bu`dahu, 'anta 'as-sahibu fissafari, wal-khalifatu fil 'ahli, allahumma 'innee 'a`outhu bika min wa`tha'is-safari, wa ka'abatil-manthari, wa sou'il munqalabi fil mali wal 'ahli (213).

Then when he would return he would say the same words, and would add to them: 'ayiboona, ta'iboona, `abidoona, li-rabbina hamidoona (214).

Footnotes.
(211) Allah is greater [than everything].
(212) Surat 'Az-Zukhruf (#43) Glory be to Him who has availed this to our use, for we were not bound to it. And to our Lord surely we will be returning (V 13, 14).
(213) O' my ilah we ask You in this journey of ours reverence and piety, and deeds that You approve of, O' my ilah facilitate this journey for us, fold up its distance for us, You are the companion in journey, and the One that remains guardian over the family, O' my ilah I solicit Your protection frm the hardship of journeying, distressful scenery, and ill happenings regarding property and family.
(214) Coming back [we are]; in repentance; in worship; and of our Lord, in praise.

Reporters.
Reported by Muslim, and is #139 in The Authentic of Good Sayings.