وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ رَبِيعَةَ بْنِ أَبِي عَبْدِ الرَّحْمَنِ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، كَانَ إِذَا جَاءَ الْمَسْجِدَ - وَقَدْ صَلَّى النَّاسُ - بَدَأَ بِصَلاَةِ الْمَكْتُوبَةِ وَلَمْ يُصَلِّ قَبْلَهَا شَيْئًا ‏.‏

Yahya related to me from Malik from Rabia ibn Abi Abd ar-Rahmanthat if Abdullah ibn Umar arrived at the mosque and the people hadalready prayed, he would begin with the obligatory prayer and not prayanything before it. Translation Not Available

Book Ref: Muwatta Imam Malik Book 9 Hadith 409
Web Ref:  Muwatta Imam Malik Book 9 Hadith 78