Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "Whoever frees a slave, the slave's property is his (the slave's), unless the master stipulates that the property will be his."
In the narration of Ibn Wahb from Ibn Lahi'ah and al-Layth bin Sa'd, the wording is: "Whoever frees a slave who has property, the slave's property is his, unless the master stipulates (otherwise)."
This contradicts the narration of the group from Nafi'; the huffaz narrated it from Nafi', from Ibn Umar, from Umar, as preceded.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب البيوع / 10764