as indeed in olden times some Fathers prayed day and night. Nay,
there is no Christian who does not have time to pray without
ceasing. But I mean the spiritual praying, that is: no one is so
heavily burdened with his labor, but that if he will he can,
while working, speak with God in his heart, lay before Him his
need and that of other men, ask for help, make petition, and in
all this exercise and strengthen his faith.

This is what the Lord means, Luke xviii, when He says, "Men ought
always to pray, and never cease," although in Matthew vi. He
forbids the use of much speaking and long prayers, because of
which He rebukes the hypocrites; not because the lengthy prayer
of the lips is evil, but because it is not that true prayer which
can be made at all times, and without the inner prayer of faith
is nothing. For we must also practise the outward prayer in its
proper time, especially in the mass, as this Commandment
requires, and wherever it is helpful to the inner prayer and
faith, whether in the house or in the field, in this work or in
that; of which we have no time now to speak more. For this
belongs to the Lord's Prayer, in which all petitions and spoken
prayer are summed up in brief words.

VIII. Where now are they who desire to know and to do good works?
Let them undertake prayer alone, and rightly exercise themselves
in faith, and they will find that it is true, as the holy Fathers
have said, that there is no work like prayer. Mumbling with the
mouth is easy, or at least considered easy, but with earnestness
of heart to follow the words in deep devotion, that is, with
desire and faith, so that one earnestly desires what the words
say, and not to doubt that it will be heard: that is a great deed