أَخْبَرَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، عَنْ سُفْيَانَ، - وَهُوَ ابْنُ حَبِيبٍ - عَنْ شُعْبَةَ، عَنْ زُبَيْدٍ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي لَيْلَى، عَنْ عُمَرَ، قَالَ صَلاَةُ الْجُمُعَةِ رَكْعَتَانِ وَالْفِطْرِ رَكْعَتَانِ وَالنَّحْرِ رَكْعَتَانِ وَالسَّفَرِ رَكْعَتَانِ تَمَامٌ غَيْرُ قَصْرٍ عَلَى لِسَانِ النَّبِيِّ صلى الله عليه وسلم ‏.‏

It was narrated that 'Umar said: "The prayer for jumu'ah is two rak'ahs, and for Al-Fitr is two rak'ahs, and for An-Nahr is two rak'ahs, and for traveling is two rak'ahs, complete and not shortened, on the tongue of the Prophet (PBUH)." Translation Not Available

Book reference: Sunan An Nisai Book 15 Hadith 1440
Web reference: Sunan An Nisai Volume 2 Book 15 Hadith 1441