Does a pitcher have to entirely hide or 'glove' the ball before starting the pitch?

[The Man In Blue]

Responding again at this time because possibly the way the rule is written *particularly with a *time frame in it and not indicating there can be constant motion or no pause needed leaves a vague area for people to try to interpret it. That was why previously I asked you for your further explanation to detail it.

Of the "Big 4" that I posted, only USA does not expressly address it. NCAA, NFHS, and USSSA all expressly say the hands can be in motion.

USA does not say the hands must be still.