1) http://www.hebrewbooks.org/pdfpager.aspx?req=920&st=&pgnum=69&hilite=
2) http://www.hebrewbooks.org/pdfpager.aspx?req=920&st=&pgnum=69&hilite=
3) http://www.hebrewbooks.org/pdfpager.aspx?req=920&st=&pgnum=69&hilite=
I understand it as an “umdina d’muchach” that if he is selling it, he doesn’t relinquish his rights, so infringinging on them is gezel. If you have a different explanation, feel fee to share.