Can the Product Owner speak at the Daily Scrum?

In a nutshell, "Yes."

In the Scrum framework, the Daily Scrum is a collaborative planning event to adapt the team's plan based on current progress towards the Sprint Goal. The 2020 version of The Scrum Guide states that this event is "for the Developers." Earlier versions of the Scrum Guide went so far as to state that "The Scrum Master enforces the rule that only Development Team members participate."

This limitation to "Developers" is what has likely led to some confusion over whether the Product Owner is allowed to speak or participate at all in this event.

So why do I state unequivically, "Yes, the Product Owner can speak!"