عَنْ أَبِيْ ذَرٍّ رَضِيَ اللّٰهُ عَنْهُ قَالَ، قَالَ لِيْ رَسُوْلُ اللّٰهِ صَلَّي اللّٰهُ عَلَيْهِ وَ سَلَّمَ كَيْفَ أَنْتَ إِذَا كَانَتْ عَلَيْكَ أُمَرَاءُ يُؤَخِّرُوْنَ الصَّلَاةَ عَنْ وَقْتِهَا أَوْ يُمِيْتُوْنَ الصَّلَاةَ عَنْ وَقْتِهَا قَالَ قُلْتُ فَمَا تَأْمُرُنِيْ قَالَ صَلِّ الصَّلَاةَ لِوَقْتِهَا فَإِنْ أَدْرَكْتَهَا مَعَهُمْ فَصَلِّ فَإِنَّهَا لَكَ نَافِلَةٌ
Hazrat Abu Dharrra narrates, “The Holy Prophetsa said to me, ‘How would you act when you are under the rulers who would delay the prayer beyond its prescribed time, or they would make prayer a dead thing as far as its proper time is concerned?’ I said, ‘What do you command?’ He said, ‘Observe the prayer at its proper time, and if you can say it along with them, do so, for it would be a supererogatory prayer for you.’”
(Sahih Muslim, Kitab al-Masajid wa muwazi al-Salat, Hadith 648a)