It was said of Rabbi Elimelech that he would deliberately take out his watch during prayer in order to break the headlong rush of the soul to God–so as to return to the reality of time.
Utmost devotion is thus seen as an intrinsic quality of the soul.
And when the scriptural text demands the love of a man "with all thy soul," the intention is total offering of the being, not only the externals of thought, speech, and action.
Indeed, there are two meanings to the command "with all thy soul."
One refers to all the different parts of the soul.
The second requires the whole of oneself, without reserve.
The first is a deliberate subservience of the various modes of one's existence to God.
The second is complete devotion expressed as an unthinking offering of one's soul.
Since this utmost devotion is beyond the mental, there cannot be a rational reason for it.
One is unable even to say why, since any sensible cause for action is a product of self-interest.
–Rabbi Adin Steinsaltz
From The Candle of God by Rabbi Adin Steinsaltz