The Kavana of Tefilla is part of the Mitzva and it is the feelings in the heart. Kavana normally means the mind; and this involves three ideas 1) Thinking that this is a commandment of God, 2) Thinking what is the specific intent of this particular commandment, 3) Thinking what the meaning of the words of the passage one is reciting while doing any Mitzva that involves recitation. We are speaking here (about Tefilla), in Davening, about ‘Kavanas HaLev’ the feelings in the heart. This is not the meaning behind the Mitzva of prayer, it IS the Mitzva of Prayer. Page 186.