Glenn was responding to the controversy caused by Manchester City manager Pep Guardiola, who violated the ban on political symbols by wearing a yellow ribbon in support of Catalan separatists.
The FA boss was defending the FA's position of allowing remembrance poppies over other political symbols when he underlined some of the things that are considered "highly divisive."
"That could be strong religious symbols, it could be the Star of David, it could be the hammer and sickle, it could be a swastika, anything like (former Zimbabwe president) Robert Mugabe on your shirt — these are the things we don't want."
Of course, contrary to some of the other mentioned symbols, the Star of David is actually an official state symbol, gracing both the Israeli flag and the kits of the Israeli national players.
Glenn quickly realized his misstep, issuing the following statement:
"I would like to apologise for any offense caused by the examples I gave when referring to political and religious symbols in football, specifically in reference to the Star of David, which is a hugely important symbol to Jewish people."