Who does Israel belong to?   An Israeli Sense of Humor at UN set the record straight.   An ingenious example of speech and politics occurred recently in the United Nations Assembly and made the world community smile.           A representative from Israel began: 'Before  beginning my talk I want to tell you something about Moses: When he struck the rock and it brought forth water, he thought, 'What a good opportunity to have a bath!'          Moses removed his clothes, put them aside on the rock and entered  the  water.  When he got out and wanted to dress, his clothes had vanished.  A Palestinian had stolen them!          The Palestinian representative jumped up furiously and shouted, 'What are you talking about? The Palestinians weren't there then.'         The Israeli representative smiled and said, 'And now that we have  made  that clear, I will begin my speech...'.