For when you cannot receive Communion: at home, when ill, or not yet able to.
A prayer of desire for Jesus in the Eucharist, when receiving him sacramentally is not possible.
When: When sick or travelling, when not able to receive at Mass, while watching Mass from home, or any time during the day.
Why: The saints taught that a real desire for Communion brings real grace. It keeps the heart turned toward the Eucharist between Masses.
My Jesus, I believe that you are present in the Most Holy Sacrament. I love you above all things, and I desire to receive you into my soul. Since I cannot at this moment receive you sacramentally, come at least spiritually into my heart. I embrace you as if you were already there and unite myself wholly to you. Never permit me to be separated from you. Amen.