Can I undo withdrawing a posted comment?

I was just posting a ‘thanks for the great octopus technique and recipe ideas’ reply (on my iPad), but when I saw it appear after a different comment by the same person - at the very bottom of the thread - I mistakenly thought I’d attached it to the wrong post and withdrew it. Once I refreshed, though, I saw that it had ended up in the right place after all, but now I don’t know how to, or if I even can, undo the withdrawal. Suggestions?

Why not just repost?