Hadith 8:2970
Abu Bakr narrated to us, he said: Hafs narrated to us, from Ibn Jurayj, he said: I asked Nafi’, "Did Ibn Umar perform ghusl (full-body ablution) upon entering Ihram?" He said: "He would sometimes perform ghusl, and he would sometimes perform wudu (partial ablution)."
حدثنا أبو بكر قال نا حفص عن بن جريج قال سألت نافعا كان بن عمر يغتسل عند الإحرام فقال كان ربما يغتسل وربما توضأ