Gaza has a sizable coastline, and China has a large number of amphibious assault ships available. They can defend themselves against Israel air attacks. If China decides to send humanitarian relief to Gaza, China can do it, and Israel can't stop them.[3] China would look like the good guys. Which their leadership knows.
[1] https://www.foreignaffairs.com/china/chinas-game-gaza
[2] https://edition.cnn.com/middleeast/live-news/israel-hamas-wa...
[3] https://www.newsweek.com/china-amphibious-assault-ship-type-...
However, situations like this, in which rhetoric and de jure policy conflict with de facto reality, open one up to others taking the fiction at face value. And what do you do then? Can't deny it without causing other problems. So now this may be regarded as an international matter because Gaza "isn't part of Israel".