On December 11, 1948 the United Nations General Assembly passed Resolution 194 that was overwhelmingly supported by most of the member states. Among other rights enshrined for Palestinians, this resolution explicitly states that Palestinian refugees have the right to return to their country in addition to the right for compensation for their lost property
Article 11:

Resolves that the refugees wishing to return to their homes and live at peace with their neighbours should be permitted to do so at the earliest practicable date, and that compensation should be paid for the property of those choosing not to return and for loss of or damage to property which, under principles of international law or in equity, should be made good by the Governments or authorities responsible.