Under a bill passed into law today, any future agreement by an Israeli government to transfer territory to another state would be subject to a referendum. The law applies to the Golan Heights and those parts of Jerusalem that are over the Green Line that divided the city between 1948 and 1967. It does not apply to Judea and Samaria/West Bank (because the latter has never been designated as territory of the State of Israel).
Israel has no tradition of national referenda, so quite apart from the consequences this law may have for potential peace agreements, it represents a significant departure from the pure form of parliamentary sovereignty that has prevailed up to now.
ADDENDUM: A transfer of territory would require a majority in a national referendum or 80 votes in the Knesset (a two-thirds majority), according to IBA.