وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، أَنَّ سَعْدَ بْنَ أَبِي وَقَّاصٍ، كَانَ يُوتِرُ بَعْدَ الْعَتَمَةِ بِوَاحِدَةٍ ‏.‏ قَالَ مَالِكٌ وَلَيْسَ عَلَى هَذَا الْعَمَلُ عِنْدَنَا وَلَكِنْ أَدْنَى الْوِتْرِ ثَلاَثٌ ‏.‏

Yahya related to me from Malik from Ibn Shihab that Sad ibn AbiWaqqas used to pray witr after isha with one raka. Maliksaid, "This is not the situation with us. Rather three is the minimumfor witr." Translation Not Available

Book reference: Muwatta Imam Malik Book 7 Hadith 213
Web reference: Muwatta Imam Malik Book 7 Hadith 213