“Our struggle against the Jews is very great and very serious. It needs all sincere efforts. It is a step that inevitably should be followed by other steps. The Movement is but one squadron that should be supported by more and more squadrons from this vast Arab and Islamic world, until the enemy is vanquished and Allah’s victory is realised.” - Hamas Covenant 1988
“Our struggle against the Jews is very great and very serious. It needs all sincere efforts. It is a step that inevitably should be followed by other steps. The Movement is but one squadron that should be supported by more and more squadrons from this vast Arab and Islamic world, until the enemy is vanquished and Allah’s victory is realised.” - Hamas Covenant 1988
The conflict predates Hamas by a few decades
A few millennium actually, however Hamas is the current acting government of Gaza, thus the cause for concern.