وَعَن أبي هُرَيْرَة قَالَ
إِنَّ رَجُلًا كَانَ يَدْعُو بِأُصْبُعَيْهِ فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «أَحِّدْ أَحِّدْ»
Abu Hurayrah told how when a man was making supplication using two of his fingers, God’s Messenger said, “Use one, use one.” It is transmitted by Tirmidhi and Nasai and by Baihaqi in ad-daawat al kabir.