Al-Adab Al-Mufrad, Book 41, Hadith 3 (In-Book)

'Abdullah ibn as-Samit said, "I questioned my close friend Abu Dharr who said, 'I brought some water for wudu' to the Prophet, may Allah bless him and grant him peace. He shook his head and bit his lip. I said, "May my father and mother be your ransom, have I injured you?" "No," he replied, "but you will meet amirs ? or imams ? who will delay the prayer until it is past its time." "So what do you command me to do?" I asked. He replied, "Pray the prayer at the proper time. If you come across them, then pray with them and do not say, 'I have already prayed, so I will not pray again.'"'"

حَدَّثَنَا مُوسَى، قَالَ‏:‏ حَدَّثَنَا وُهَيْبٌ، قَالَ‏:‏ حَدَّثَنَا أَيُّوبُ، عَنْ أَبِي الْعَالِيَةِ قَالَ‏:‏ سَأَلْتُ عَبْدَ اللهِ بْنَ الصَّامِتِ قَالَ‏:‏ سَأَلْتُ خَلِيلِي أَبَا ذَرٍّ، فَقَالَ‏:‏ أَتَيْتُ النَّبِيَّ صلى الله عليه وسلم بِوَضُوءٍ، فَحَرَّكَ رَأْسَهُ، وَعَضَّ عَلَى شَفَتَيْهِ، قُلْتُ بِأَبِي أَنْتَ وَأُمِّي آذَيْتُكَ‏؟‏ قَالَ‏:‏ لاَ، وَلَكِنَّكَ تُدْرِكُ أُمَرَاءَ أَوْ أَئِمَّةً يُؤَخِّرُونَ الصَّلاَةَ لِوَقْتِهَا، قُلْتُ‏:‏ فَمَا تَأْمُرُنِي‏؟‏ قَالَ‏:‏ صَلِّ الصَّلاَةَ لِوَقْتِهَا، فَإِنْ أَدْرَكْتَ مَعَهُمْ فَصَلِّهِ، وَلاَ تَقُولَنَّ‏:‏ صَلَّيْتُ، فَلاَ أُصَلِّي‏.‏

sunnah.com