If you’ve ever paid close attention to Star Wars, you might notice that certain key lines of dialogue seem to echo across stories and characters. “Rebellions are built on hope” is one such key line. We first hear Cassian deliver it to Jyn Erso in Rogue One, and she then uses it with the rebel council to convince them to go after the Death Star plans.

Now, thanks to Andor, we know that that line originated with Ghorman bellhop Thela, who delivers it to Cassian just before he throws a bomb that blows up part of the imperial army. That line’s echoes and reverberations are hugely important to the overall shape of the rebellion, but it turns out that showrunner Tony Gilroy didn’t originally plan to include it.

“My son is a big Star Wars fan, and he often comes to the house and busts my balls at the computer about how little I know,” Gilroy told Entertainment Weekly. “One day he’s there at the house and he’s goofballing on me, and he’s like, ‘Well, who’s going to introduce ‘rebellions are built on hope’?”

“And I go, ‘What do you mean?’” Gilroy added. “He goes, ‘Well, in Rogue One, Diego says it. And Jyn repeats it.’ And I go, ‘Well, isn’t that from somewhere?’ He goes, ‘No, man, what are you talking about? You better figure that out.’”

By the time Tony and his son discussed this, there wasn’t much time to figure out how to include it, so he decided to give the line to a relatively minor character. “The hotel clerk is such a groovy little character,” he says. “It definitely comes from my son busting me on not having it in earlier [scripts]. I was like, ‘Good catch.’ So that’s where it comes from.”

It might not have been hugely thought through, but it undoubtedly adds more resonance to the use of that line in Rogue One.