It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that Sawwar bin Shabib asked him about performing the prayer during travel, and he said that the Messenger of Allah (peace and blessings be upon him) said: "(The prayer while travelling is) two rak'ahs, two rak'ahs, except the Maghrib prayer (which remains in its original form, that is, three rak'ahs, even while travelling)."
Imam Abu Dawud al-Tayalisi recorded this hadith in his Musnad and its chain is jayyid (good), while the basis for shortening the four-rak'ah prayers to two rak'ahs during travel is also established by narrations of Sahih al-Bukhari and Sahih Muslim.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / أبواب الجمعة / 737
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :صحيح لغيره. » «أخرجه الترمذي فى «جامعه» برقم: 551، وابن ماجه فى «سننه» برقم: 1193، 1194، والبيهقي فى«سننه الكبير» برقم: 5501، وأحمد فى «مسنده» برقم: 2190، والطيالسي فى «مسنده» برقم: 2061، وأورده ابن حجر فى "المطالب العالية"، 737»