Narrated Ibn `Umar: I accompanied Allah's Apostle and he never offered more than two rak`at during the journey. Abu Bakr, `Umar and `Uthman used to do the same.
Hadith Referenceصحيح البخاري / كتاب تقصير الصلاة / 1102
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة