Sahih Muslim 648 f
Abu Dharr reported:
(The Messenger of Allah) said: How would you, or how would thou, act if you survive to live among people who defer prayer beyond the (prescribed) time? (The narrator said: Allah and His Messenger know best). whereupon he said: Observe prayer at its prescribed time, but if the Iqama is pronounced for (congregational) prayer, then observe prayer along with them. for herein is an excess of virtue.
وَحَدَّثَنَا عَاصِمُ بْنُ النَّضْرِ التَّيْمِيُّ، حَدَّثَنَا خَالِدُ بْنُ الْحَارِثِ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي نَعَامَةَ، عَنْ عَبْدِ اللَّهِ بْنِ الصَّامِتِ، عَنْ أَبِي ذَرٍّ، قَالَ قَالَ ‏
"‏ كَيْفَ أَنْتُمْ - أَوْ قَالَ كَيْفَ أَنْتَ - إِذَا بَقِيتَ فِي قَوْمٍ يُؤَخِّرُونَ الصَّلاَةَ عَنْ وَقْتِهَا فَصَلِّ الصَّلاَةَ لِوَقْتِهَا ثُمَّ إِنْ أُقِيمَتِ الصَّلاَةُ فَصَلِّ مَعَهُمْ فَإِنَّهَا زِيَادَةُ خَيْرٍ ‏"‏ ‏.‏