He only said, "Enter all of me," because of the smallness of the dome.
حدثنا صفوان بن صالح حدثنا الوليد
إنما قال أدخل كلي من صغر القبة
No references are available.
Its isnad is sahih. Bayhaqi (10/248) narrated it from the hadith of Abu Dawud through this chain.Uthman bin Abu Atikah is daif, but the chain to him is sahih.