This Communion is number 15 of the École d'Orgue.
It has something not often seen elsewhere that makes it difficult to play. About halfway the piece the hands not only change manual (that is of course fairly common) they change staff as well. Suddenly the first staff is to be played by the left hand and the middle staff by the right hand.
It took a bit of time before my hands agreed on which notes each one should play.
Try it yourself, the score is here: