The most serious genocide we're all aware of began, indeed, with a terrorist incident (https://en.wikipedia.org/wiki/Kristallnacht) -- a jewish boy assassinated a german diplomat.
This comment also conflates Hamas with the civilian population of gaza. The genocide isnt against Hamas -- we all regard israel's killing of enemy military combtants as not included in this crime.
Here's an interview with a senior UNICEF worker about israel's actions against the civilian population : https://www.youtube.com/watch?v=NsAo2j6aih0
This is not about israel incidentally hitting civilians. It's about the deliberate policy of mass starvation, withholding of medical supplies (incubators, pain killers, the lot), and the placing of the only "allowed" aid-distribution centres (4 out of a previous 400) in the middle of active war zones -- so that to recieve any aid at all, you have to go through active fire.
This has nothing to do with israel's actions against Hamas