In affections and prayers it is, then, that the soul should entertain itself with Jesus after Communion; for we must know, that the acts formed in prayer after Communion are far more precious and meritorious in the sight of God than when made at another time; for the soul being then united with Jesus, the value of the acts is increased by the presence of Jesus. We should, moreover, know, that after Communion Jesus Christ is more disposed to grant graces.
--St. Alphonsus Liguori, The Holy Eucharist