Musar su Salmi 55:23

The wise man said : Every man needs a fence and support in order that his good deeds should be brought to fulfillment. And what is the fence? It is complete trust — to always trust in God, may He be Blessed, as it is said : "Cast your burden upon the Lord and He will sustain you" (Ps. 55:23).

The Kabbalists warn that one must not travel alone without contemplating thoughts of Torah or fear of Heaven lest the Sitrah Acharah cling to him. The Zohar states clearly (Parashas Vayishlach 169b) that even in town if a person is out alone at an hour that people are not usually found on the street the Sitrah Acharah will cling to him and he will not escape without committing some iniquity that very day. Therefore he must conduct himself in the following manner: If he plans on going out alone to tend to his affairs very early or very late in the day when few people are around, let him recite in front of the mezuzah the verse, “Cast your burden upon Hashem and He will provide for you” (Tehillim 55:23). And when he comes to the Divine name let him envision it with the vowels of the word yehavcha (“He will provide for you”), that is, with a sheva beneath the yud, a kamatz beneath the first hei, a sheva beneath the vav and a kamatz beneath the second hei. Since a sheva resembles two yudim, one on top of the other, and a kamatz resembles a reclining vav with a yud beneath it, the numerical value of this vocalization is equal to six yudim and two vavim, or seventy-two. This is the same as the numerical value of the word chessed — “lovingkindness.”