عَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَجُلٌ: يَا رَسُولَ اللَّهِ! كَيْفَ تَأْمُرُنَا أَنْ نُصَلِّيَ مِنَ اللَّيْلِ؟ قَالَ: ((يُصَلِّي أَحَدُكُمْ مَثْنَى مَثْنَى فَإِذَا خَشِيَ الصُّبْحَ صَلَّى وَاحِدَةً فَأَوْتَرَتْ لَهُ مَا قَدْ صَلَّى مِنَ اللَّيْلِ))
It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with him) that a man said: O Messenger of Allah! How do you command us to pray at night? The Prophet (peace and blessings be upon him) said: A person should keep praying two rak‘ahs at a time; when he fears that dawn is about to break, he should pray one rak‘ah. This one rak‘ah will make the number of rak‘ahs he has prayed during the night odd.