Pitcher obstruction?

[jbarry06248]

A pitcher puts out his foot to stop a ground ball from going up the middle. The ball deflects off foot towards first base line. Pitcher chases ball. When pitcher gets to ball, using a sitting slide, he is in the base line. The runner is forced to dive over him and doesn't reach base. Pitcher throws out runner while runner is still lying on ground.

Is this obstruction? Is the initial attempt to stop the ball with the foot considered a play at the ball, or is it all one continuous play?

Also, I cannot find any detail on this in rule book. Where might I find the rule on this?

Thanks,

John