Bulugh al-Maram
Book 2, Hadith 229
Arabic hadith text
وَلِأَبِي دَاوُدَ , فَقَالَ : { أَصَدَقَ ذُو اَلْيَدَيْنِ ? " فَأَوْمَئُوا : أَيْ نَعَمْ } . 11 - صحيح . رواه أبو داود ( 1008 ) .
Translation
And in Abu Dawud
"He said, 'Has Dhul-Yadain spoken the truth?' Then they said 'Yes' with gesture".