Muwatta Imam Malik Book of Tahajjud, Hadith 12
Yahya related to me from Malik from Abdullah ibn Abi Bakr from his father that Abdullah ibn Qays ibn Makhrama told him that Zayd ibn Khalid al-Juhani said one night that he was going to observe the prayer of the Messenger of Allah, may Allah bless him and grant him peace. He said, "I rested my head on his threshold. The Messenger of Allah ﷺ got up and prayed two long, long, long rakas. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed an odd raka, making thirteen rakas in all."
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَكْرٍ، عَنْ أَبِيهِ، أَنَّ عَبْدَ اللَّهِ بْنَ قَيْسِ بْنِ مَخْرَمَةَ، أَخْبَرَهُ عَنْ زَيْدِ بْنِ خَالِدٍ الْجُهَنِيِّ، أَنَّهُ قَالَ لأَرْمُقَنَّ اللَّيْلَةَ صَلاَةَ رَسُولِ اللَّهِ ﷺ - قَالَ - فَتَوَسَّدْتُ عَتَبَتَهُ - أَوْ فُسْطَاطَهُ - فَقَامَ رَسُولُ اللَّهِ ﷺ فَصَلَّى رَكْعَتَيْنِ طَوِيلَتَيْنِ طَوِيلَتَيْنِ طَوِيلَتَيْنِ ثُمَّ صَلَّى رَكْعَتَيْنِ وَهُمَا دُونَ اللَّتَيْنِ قَبْلَهُمَا ثُمَّ صَلَّى رَكْعَتَيْنِ وَهُمَا دُونَ اللَّتَيْنِ قَبْلَهُمَا ثُمَّ صَلَّى رَكْعَتَيْنِ وَهُمَا دُونَ اللَّتَيْنِ قَبْلَهُمَا ثُمَّ صَلَّى رَكْعَتَيْنِ وَهُمَا دُونَ اللَّتَيْنِ قَبْلَهُمَا ثُمَّ صَلَّى رَكْعَتَيْنِ وَهُمَا دُونَ اللَّتَيْنِ قَبْلَهُمَا ثُمَّ أَوْتَرَ فَتِلْكَ ثَلاَثَ عَشْرَةَ رَكْعَةً .