Is it authentically reported that Umar ibn al-Khattab (may Allah be pleased with him) said: "The Muslims will consume them as long as they are alive, and if we perish and they perish, our children will consume their children as long as they remain"?

The statement attributed to Omar (may Allah be pleased with him) has no connected, authentic chain of transmission that we have found. It appeared in the book "Al-Kharaj" by Qadi Abu Yusuf without a chain of transmission, within a letter from Omar to Abu Ubaydah. This letter stated that if the jizyah is taken from the People of the Book, then there is no claim against them. He reasoned that Muslims would "eat them" as long as they were alive, and their children would "eat their children," meaning they would be servants to Muslims as long as the religion of Islam was manifest. Then, he commanded him to impose the jizyah on them, refrain from enslaving them, prevent Muslims from oppressing or harming them, and from consuming their wealth except through lawful means, and to fulfill the conditions of their agreement with them.