…the 6th treatise, the Letter F, this Letter advises those who wish to make further progress and follow better things to accustom themselves to “recollection”, for they will thus imitate and follow our Lord, whose custom it was to go into the desert, where, alone and recollected, he could pray more secretly and spiritually to his and our Heavenly Father.

pg. 97, para. 3: Hence this Letter directs: “Frequently practise recollection in order to train yourself in its use”.