Muwatta Malik
Shortening the Prayer
Hadith #16
9.16
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّهُ كَانَ يُسَافِرُ مَعَ ابْنِ عُمَرَ الْبَرِيدَ فَلاَ يَقْصُرُ الصَّلاَةَ .
Yahya related to me from Malik from Nafi that he used to travel one mail-stage with Ibn Umar, and he would not shorten the prayer