I would like to congratulate the anonymous reader who correctly named this plant the pomelo.
We were first introduced to pomelos while visiting Max in his village. Cale and Max had gone for a walk and returned with a huge one. According to Max, they are very popular in Israel. I find them to be a sweeter version of grapefruit and like them more than either grapefruits or oranges.
According to Wikipedia, it is the largest citrus fruit and is one half of the tangelo hybrid (half pomelo, half tangerine).