The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1468
Hafs b. 'Asim reported: I fell ill and lbn 'Umar came to inquire after my health, and I asked him about the glorification of Allah (i. e. prayer) while travelling. Thereupon he said: I accompanied the Messenger of Allah (may peace be upon him) on a journey but I did not see him glorifying Him, and were I to glorify (Him). I would have completed the prayer. Allah, the Exalted, has said:" Verily there is a model pattern for you in the Messenger of Allah."