Abu Zabyan narrates from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) as a marfu' report: "Any boy who performs Hajj and then reaches puberty, another Hajj is obligatory upon him; any Bedouin who performs Hajj and then emigrates, another Hajj is due from him as well; and any slave who performs Hajj and is then set free, another Hajj is obligatory upon him too."
Only Muhammad bin al-Minhal narrated it as marfu', from Yazid bin Zuray', from Shu'bah; others narrated it from Shu'bah as mawquf (a saying of Ibn Abbas). Likewise Sufyan al-Thawri narrated it from al-A'mash as mawquf, and that is what is correct.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9849