That is interesting. From what I can understand of Hamas' constitution, it regards the land occupied by Israel as belonging by right to Islamic Palestine "from the river to the sea" Israel's is land is apparently considered a waqf, an inalienable possession of the Muslims.
It appears that there is a revised, less extreme version which might allow a 2 state solution, which was written around 2006 to make Hamas more widely appealing.
[From what I have read, various attempts actually to establish a 2 state solution were scuppered by extremists on both sides, basically.]
The original 9,000 word charter draws on a hadith, a prophetic saying "The Day of Judgement will not come till Muslims fight Jews and kill them. Then Jews will hide behind rocks and trees, and the rocks and trees will cry out" O Moslem, there is a Jew hiding behind me, come and kill him".
If this is behind Hamas thinking, it does help explain how threatening Israel finds it, especially in the context of the actual violence in October.