"Pass it on" literally means "tell someone else, including the words 'pass it on'" Thus, that the news will spread to everyone. Someone says "XYZ, pass it on" to you, you say "XYZ, pass it on" to someone else, and so on. It is often used by unkind elementary-school children, sitting at their desks, to spread insults and rumors about someone.. Without leaving their seat, they can lean over and whisper to a classmate. By the time the teacher notices and stops it, the damage is done. The general pattern might be something like "Danny stinks, pass it on." "Sucks" is a with complicated cultural contexts that non-native speakers should avoid. It is a very emphatic way of saying that something is bad. It is colloquial. Complaining to a restaurant about slow service, speaking politely and formally, I might say "The service was unacceptably slow." To a friend, I might say "The service stinks." To make it stronger, I might say "the service sucks." "Sucks" is very close to being taboo language. It is angry and hostile. You can't use it in a joking, "just-kidding" way. If "Israel" were referring to a national sports team, perhaps in the World Cup or something like that, then it MIGHT just barely be acceptable. In the United States, there is a long-standing rivalry between the two baseball teams, the New York Yankees and the Boston Red Sox, and for a while it was popular for Red Sox fans to wear shirts that said "Yankees suck." However, it sounds like an insult to the nation of Israel. Perhaps that is not an extreme view in Egypt. In the United States and most English-speaking countries it would be unacceptable, verging on "hate speech."

Can you provide the context where you found this? Because it is a statement that contains a negative comment on an entire nation, and asks others to share in this opinion. As such, if you knew what it meant, it would be highly inappropriate to post on this website.