The Messenger of Allah ﷺ saw a person praying after the congregational prayer at dawn was over. The Messenger of Allah ﷺ said: There are two rak'ahs of the dawn prayer (i.e. the prescribed rak'ahs). The man replied: I did not pray the two rak'ahs before the dawn prayer. Hence I offered them now. The Messenger of Allah ﷺ kept silent.  

رَأَى رَسُولُ اللَّهِ ﷺ رَجُلاً يُصَلِّي بَعْدَ صَلاَةِ الصُّبْحِ رَكْعَتَيْنِ فَقَالَ رَسُولُ اللَّهِ ﷺ صَلاَةُ الصُّبْحِ رَكْعَتَانِ فَقَالَ الرَّجُلُ إِنِّي لَمْ أَكُنْ صَلَّيْتُ الرَّكْعَتَيْنِ اللَّتَيْنِ قَبْلَهُمَا فَصَلَّيْتُهُمَا الآنَ فَسَكَتَ رَسُولُ اللَّهِ ﷺ  

'Abd Rabbihi and Yahya b. Sa'id also narrated this tradition from the Prophet ﷺ omitting the name of the Companion (mursal). Their grandfather Zaid prayed along with the Prophet ﷺ.