Secret meals make fat bodies

(Thomas Brooks, "The Privy Key of Heaven" 1665)

"But when you pray, go into your private room, shut your
 door, and pray to your Father who is in secret." Mat. 6:6

Secret duties are the most soul-enriching duties. Look! as
secret meals make fat bodies—so secret duties make
fat souls! And as secret trades brings in great earthly riches,
so secret prayers makes many rich in spiritual blessings and
in heavenly riches. Private prayer is that secret key of heaven
which unlocks all the treasures of glory to the soul. The best
riches and the sweetest mercies, God usually gives to His
people—when they are in their closets upon their knees.

All the graces of the saints are enlivened, and nourished, and
strengthened by the sweet secret influences which their souls
fall under, when they are in their closet-communion with God.
Certainly there are none so rich in gracious experiences—as
those who are most exercised in closet duties.

The tender dew which falls in the silent night makes the
grass and herbs and flowers to flourish and grow more
abundantly—than great showers of rain which fall in the day.
Just so, secret prayer will more abundantly cause the sweet
flowers of grace and holiness to grow and flourish in the soul,
than all those more open, public, and visible duties of religion,
which too, too often, are mingled and mixed with the sun and
wind of pride and hypocrisy.

"Devote yourselves to prayer, being watchful and thankful."
     Colossians 4:2