وَحَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم صَلَّى الصَّلاَةَ الرُّبَاعِيَّةَ بِمِنًى رَكْعَتَيْنِ وَأَنَّ أَبَا بَكْرٍ صَلاَّهَا بِمِنًى رَكْعَتَيْنِ وَأَنَّ عُمَرَ بْنَ الْخَطَّابِ صَلاَّهَا بِمِنًى رَكْعَتَيْنِ وَأَنَّ عُثْمَانَ صَلاَّهَا بِمِنًى رَكْعَتَيْنِ شَطْرَ إِمَارَتِهِ ثُمَّ أَتَمَّهَا بَعْدُ ‏.‏

Yahya related to me from Malik from Hisham ibn Urwa from hisfather that the Messenger of Allah, may Allah bless him and grant himpeace, prayed four raka prayers with only two rakas when at Mina, andthat Abu Bakr prayed them at Mina with only two rakas, and that Umaribn al-Khattab prayed them at Mina with only two rakas, and thatUthman prayed them at Mina with only two rakas for half of hiskhalifate, and then later completed them. Translation Not Available

Book Ref: Muwatta Imam Malik Book 20 Hadith 908
Web Ref:  Muwatta Imam Malik Book 20 Hadith 210