It appears to be a kind of fig tree (perhaps similar to the fiddle leaf fig tree but without the fiddle?), although the leaf shape doesn't match. It didn't seem very appealing to eat (!), it was oozing white sap from the stem and from the fruit itself when i broke it apart.
The fruit felt like a hard sponge.
I found the tree in Israel, although, in this location there are a number of non-indigenous trees.