[Machine] The Messenger of Allah ﷺ said, "The night prayer should be performed in sets of two. When you see that dawn is approaching, then conclude with one unit of prayer." A man asked Ibn Umar, "What does 'sets of two' mean?" He replied, "You make Salaam after every two units of prayer."
قَالَ رَسُولُ اللهِ ﷺ صَلَاةُ اللَّيْلِ مَثْنَى مَثْنَى فَإِذَا رَأَيْتَ أَنَّ الصُّبْحَ مُدْرِكُكَ فَأَوْتِرْ بِرَكْعَةٍ فَقَالَ رَجُلٌ لِابْنِ عُمَرَ مَا مَثْنَى؟ قَالَ تُسَلِّمُ فِي كُلِّ رَكْعَتَيْنِ
The night prayer consists of pairs and when you see the approach of dawn, make this number odd by one rak'ah. It was said to Ibn 'Umar: What does the (word) pair imply? He said: (It means) that salutation is uttered after every two rak'ahs.
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ صَلاَةُ اللَّيْلِ مَثْنَى مَثْنَى فَإِذَا رَأَيْتَ أَنَّ الصُّبْحَ يُدْرِكُكَ فَأَوْتِرْ بِوَاحِدَةٍ فَقِيلَ لاِبْنِ عُمَرَ مَا مَثْنَى مَثْنَى قَالَ أَنْ يُسَلِّمَ فِي كُلِّ رَكْعَتَيْنِ
The night prayer consists of pairs and when you see the approach of dawn, make this number odd by one rak'ah. It was said to Ibn 'Umar: What does the (word) pair imply? He said: (It means) that salutation is uttered after every two rak'ahs. (Using translation from Muslim 749i)
عَنْ رَسُولِ اللهِ ﷺ قَالَ صَلَاةُ اللَّيْلِ مَثْنَى مَثْنَى فَإِذَا رَأَيْتَ أَنَّ الصُّبْحَ يُدْرِكُكَ فَأَوْتِرْ بِوَاحِدَةٍ قَالَ فَقِيلَ لِابْنِ عُمَرَ مَا مَثْنَى مَثْنَى قَالَ تُسَلِّمُ فِي كُلِّ رَكْعَتَيْنِ
[Machine] The Messenger of Allah ﷺ said, "The night prayer is to be performed in pairs. If you see that dawn is about to break, then offer one odd-numbered prayer." I asked Ibn Umar, "What is meant by 'in pairs'?" He replied, "Offering the salaam (salutation) in every two units of prayer." According to the narration of Adam, he said, "Offer one odd-numbered prayer." Then a man asked Ibn Umar, "What is meant by 'in pairs'?" He replied, "Offering the salaam between every two units of prayer." It is narrated in its chain of transmission from Shu'bah that Uqbah bin Hareth said, "He (the Prophet) said..." (the rest of the sentence is cut off)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ صَلَاةُ اللَّيْلِ مَثْنَى مَثْنَى فَإِذَا رَأَيْتَ أَنَّ الصُّبْحَ يُدْرِكُكَ فَأَوْتِرْ بِوَاحِدَةٍ قُلْتُ لِابْنِ عُمَرَ مَا مَثْنَى مَثْنَى؟ قَالَ مُتَسَلِّمٌ فِي كُلِّ رَكْعَتَيْنِ لَفْظُ حَدِيثِ ابْنِ بَشَّارٍ وَفِي رِوَايَةِ آدَمَ فَأَوْتِرْ بِرَكْعَةٍ فَقَالَ رَجُلٌ لِابْنِ عُمَرَ مَا مَثْنَى مَثْنَى؟ فَقَالَ السَّلَامُ بَيْنَ كُلِّ رَكْعَتَيْنِ وَقَالَ فِي إِسْنَادِهِ عَنْ شُعْبَةَ ثنا عُقْبَةُ بْنُ حُرَيْثٍ قَالَ يَقُولُ قَالَ رَسُولُ اللهِ ﷺ
"عَنْ عُقْبَةَ بْنِ حُرَيْث قَالَ: سَمِعْتُ ابْنَ عُمَرَ يُحَدِّثُ أن رَسُولَ الله ﷺ قَالَ: صَلاَةُ اللَّيْلِ مَثْنَى مَثْنَى، فَإذَا رأَيْتَ الصُّبْحَ يُدْرِكُكَ فَأوْتِرْ بِوَاحِدَةٍ، فَقِيلَ لابنِ عُمَرَ: مَا مَثْنَى مَثْنَى؟ قالَ: تُسَلِّمُ فِى كُلِّ رَكْعَتَيْنِ".