@b870d4c8 One thing to consider is funding.  In the past, Hamas has done smaller-scale stuff of this nature when they've been cut off by one country or another, in a bid to get someone to pay them to stop, basically.  This happened after Iran cut ties when Hamas backed Sunni rebels in Syria, for example, and Egypt eventually bribed them to stop.

Alternatively, a financial backer could have persuaded them to attack as part of some larger geopolitical "chess", but only Putin would be that stupid. 

 @51928c97 absolutely, but this isn't a small attack as a negotiation. This is an all-out attack that will probably lead to a major invasion and attempt to destroy Hamas. I don't think money would convince Hamas to do this, only a belief this helps them pursue existential goals.