Well it didn’t take long. Within the first few hours of the ceasefire, Hamas has already begun launching rockets into Sderot, in Southern Israel.
Hamas has stated that they will not stop firing until Israel withdraws all troops, opens all crossings and, presumably, dies.
Israel has stated they intend to withdraw troops once Egyptian and international truce treaties are finalised, however until such time, cannot withdraw as this would simply allow Hamas to rearm and resume firing.
It’s seen here as no surprise that Hamas did not recognise a ceasefire; the only surprise is that Hamas stopped firing for a period, at all.