Intent in prayer, and the recitation of the Shema and its blessings, and other blessings, are the commandments
that are dependent on speech and enunciation,.
When a person has intent regarding them, he causes his thoughts and intellect to cleave to God.
The mitzvot mentioned here all involve speech and verbal articulation.
When performing these mitzvot, a persons intent should be to focus on the meaning of the words he is saying.
He is speaking to God, and so he must also think about God.
Intent in action and speech is accomplished by means of thought.
Speech and action are the external garments of the soul, and not necessarily connected to the faculties of the soul.
A person can speak and act in a way that is detached from his soul.
This is not true regarding thought, which is the inner garment of the soul and which is always attached to and inseparable from the faculties of the soul.
When a person not only performs a mitzva but thinks at that moment about the Commander, he attaches his soul to God.
Rabbi Adin Steinsaltz