From one of her letters
It seems to me that the commandment of love that God speaks to Moses is the weightiest. I know in scripture, “you shall love your lord, your God, with all your heart, with all your soul, and with all your strength.” These words you shall never forget, sleeping or waking. If you sleep you must dream of them. If you are awake, you must think of them and recite them, and carry them into effect. These words you shall write on the threshold, and on the lintel, and on the wall, and in all places where you shall be, that you may not forget what you must do there.
In other words, God commands that we nevermore forget love, either sleeping or waking, in any manner, with all that we are, with heart, with soul, with mind, with strength,, and with our thoughts. God gave this commandment to Moses and in the Gospels that in this way we should live wholly for love. Woe, indeed! How dare we then give love short measure in anything? Alas, it is not fearful robbery that we spare anything for love or hold back anything? Alas! Think about this, and work without neglect to promote love above all things.