Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) says that the Prophet (peace and blessings be upon him) said: "Whoever divorces what he does not own, there is no divorce for him; whoever frees a slave he does not own, there is no freeing for him; whoever makes a vow concerning what he does not own, he is not bound to fulfil the vow; whoever swears an oath to disobey Allah, there is no oath for him; and whoever swears an oath to sever ties of kinship, there is no oath for him."
An addition has been narrated in this hadith that contradicts the authentic narrations from the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19858