Husayn narrates: It reached Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that Sayyiduna Sa'd (may Allah be pleased with him) prayed witr with one rak'ah, so he said: "A single rak'ah has never sufficed."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9390