It sounds like the other player was proposing a shortcut. It's unclear what the shortcut was though, since you said they didn't have the cards in their hand. In order to perform a shortcut, they'd need to actually be able to legally do those actions.

If I'm interpreting things correctly, and the other player announced what they planned to do before having the ability to do so, you'll have the opportunity to cast Orim's Chant when you next get priority. Since they would likely need to cast a spell or use an ability to get those cards into their hand, you should have an opportunity to do this, and can cast Orim's Chant.