Jami' at-Tirmidhi
Jami` at-Tirmidhi 547
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا هُشَيْمٌ، عَنْ مَنْصُورِ بْنِ زَاذَانَ، عَنِ ابْنِ سِيرِينَ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم خَرَجَ مِنَ الْمَدِينَةِ إِلَى مَكَّةَ لاَ يَخَافُ إِلاَّ اللَّهَ رَبَّ الْعَالَمِينَ فَصَلَّى رَكْعَتَيْنِ . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ .
Unreviewed translation. All hadiths in this collection are available in five languages. Titles and introductions may remain in Arabic.
Ibn Abbas narrated: The Prophet traveled from Madinah to Makkah, fearing none but Allah, the Lord of all worlds, and prayed two units. Abu Isa said: This hadith is hasan sahih.
Notes and open questions — unreviewed
The report links the two-unit prayer to the journey; the source does not explicitly name it as a travel prayer.