Once the call (Iqama) for the prayer was announced and the rows were straightened. Messenger of Allah ﷺ came out; and when he stood up at his Musalla, he remembered that he was Junub. Then he ordered us to stay at our places and went to take a bath and then returned with water dropping from his head. He said, "Allahu-Akbar", and we all offered the prayer with him.  

أُقِيمَتِ الصَّلاَةُ وَعُدِّلَتِ الصُّفُوفُ قِيَامًا فَخَرَجَ إِلَيْنَا رَسُولُ اللَّهِ ﷺ فَلَمَّا قَامَ فِي مُصَلاَّهُ ذَكَرَ أَنَّهُ جُنُبٌ فَقَالَ لَنَا مَكَانَكُمْ ثُمَّ رَجَعَ فَاغْتَسَلَ ثُمَّ خَرَجَ إِلَيْنَا وَرَأْسُهُ يَقْطُرُ فَكَبَّرَ فَصَلَّيْنَا مَعَهُ  

Messenger of Allah ﷺ said, "Whoever could get one rakʿa of a prayer, (in its proper time) he has got the prayer."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَنْ أَدْرَكَ رَكْعَةً مِنَ الصَّلاَةِ فَقَدْ أَدْرَكَ الصَّلاَةَ