Even though he speaks of "an hour" regarding this prayer Master Samael is not referring to time exclusively Quantitatively but primarily Qualitatively. The Pater Noster shouldn't be prayed repetetively (Matthew 6:7). It is not a mere mantra to occupy the mind. Nor is it a palliative to make us feel good. Nor a lecture on Kabbalah. Master Samael is saying that one wants to penetrate into the significance of the Pater Noster. Even if one were to pray simply and intutitively, it is not a matter of how long one prays but a matter of entering into the prayer completely, so that NOT ONE WORD slips by meaninglessly, from beginning to end. How long that takes is subjective.
Our Father which art in Heaven
Hallowed be Thy Name
Why "Our"? Who is our "Father"? What and where is this "Heaven"? How is something "Hallowed"? What IS "Thy Name"? In effect, by asking "Who, what, where, when, why, and how" with our heart, our soul and our strength in concert we are turning this wonderful prayer into a form of profound concentration, not upon trivial and meaningless things, but upon who we are, why we're here and what we can do about it. Therefore, praying this prayer in the way Master Samael indicates can produce within us what is normally a rare and unfamiliar state of accord between the Three Brains, a state that every initiate aspires to.
Peace