مُوَطَّأُ مَالِكٍ
Muwatta Malik 509
The Qur'an
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، قَالَ رَآنِي عَبْدُ اللَّهِ بْنُ عُمَرَ وَأَنَا أَدْعُو، وَأُشِيرُ، بِأَصْبُعَيْنِ أَصْبُعٍ مِنْ كُلِّ يَدٍ فَنَهَانِي .
Yahya related to me from Malik that Abdullah ibn Dinar said, "Abdullah ibn Umar saw me when I was making dua and I was pointing with two fingers, one from each hand, and he forbade me."
Arabic/English book reference: Book 15, Hadith 37