كتاب 9
9  
Book 9
(9)
Chapter 9
(9)
باب 9
Muwatta Malik 333
Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to join the prayer along with the amirs if they joined maghrib and isha in the rain.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ إِذَا جَمَعَ الأُمَرَاءُ بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ فِي الْمَطَرِ جَمَعَ مَعَهُمْ ‏.‏
Reference : Muwatta Malik 333
In-book reference : Book 9, Hadith 34511
USC-MSA web (English) reference : Book 7, Hadith 333
  (deprecated numbering scheme)