Yahya related to me from Malik from Ibn Shihab that Safwan said, "Abdullah ibn Umar used to come and visit Abdullah ibn Safwan and he would pray two rakas with us, and when he went away we would stand and complete the prayer."


وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ صَفْوَانَ، أَنَّهُ قَالَ جَاءَ عَبْدُ اللَّهِ بْنُ عُمَرَ يَعُودُ عَبْدَ اللَّهِ بْنَ صَفْوَانَ فَصَلَّى لَنَا رَكْعَتَيْنِ ثُمَّ انْصَرَفَ فَقُمْنَا فَأَتْمَمْنَا ‏.‏
USC-MSA web (English) reference : Book 9, Hadith 23
Arabic reference : Book 9, Hadith 352