At the risk of having various writers "repeat themselves" (yes, I've quoted some of these before), I'd like to take a minute to recap the essence of heart monasticism as I see it......
"For the humble lay brother (Brother Lawrence), prayer was the consciousness of the continual presence of God. This realization never left him, whether he was cooking eggs in the kitchen or kneeling in the sanctuary. In order to be with God, he said, it was not necessary to remain constantly in church; man's heart, too, could be his oratory." (Walter Nigg, Warriors of God, Alfred A. Knof, 1959, p. 306)
“Always
remember… to retire at various times into the solitude of your own
heart even while outwardly engaged in discussions or transactions with
others. This mental solitude cannot be violated by the many people who
surround you since they are not standing around your heart but only
around your body. Your heart remains alone in the presence of God.” (St. Francis de Sales)
(painting of Girl Sweeping by William Paxton, 1912. In US public domain)
(painting of Girl Sweeping by William Paxton, 1912. In US public domain)