Says the HAMAS Covenant -- Article 11
The Islamic Resistance Movement believes that the land of Palestine is an Islamic Waqf consecrated for future Moslem generations until Judgement Day. It, or any part of it, should not be squandered: it, or any part of it, should not be given up. Neither a single Arab country nor all Arab countries, neither any king or president, nor all the kings and presidents, neither any organization nor all of them, be they Palestinian or Arab, possess the right to do that. Palestine is an Islamic Waqf land consecrated for Moslem generations until Judgement Day. This being so, who could claim to have the right to represent Moslem generations till Judgement Day?
Surprisingly if you substitute Jewish for Muslim this is pretty similar to the founding charter of Likud. The difference is whilst Hammas have moved on and now recognise that the right of existence for a Jewish homeland, Likud still denies the right of Palestinians to their own state. On this Hammas is actually more liberal than Likud, and the Likud are not the most extremist party in the Israeli government.