Abu Dawud Book 2, Hadith Number 902.
Chapter : Not known.
Narated By Abdullah ibn Umar : Sa’id ibn Ziyad ibn Subayh al-Hanafi said: I prayed by the side of Ibn Umar and I put my hands on my waist. When he finished his prayer, He said: This is a cross in prayer; the Apostle of Allah (PBUH) used to forbid it.