In the Lord's discourse on spiritual nourishment, we hear Him says: “Do not labor for the food which perishes, but for the food which endures to everlasting life.” (John 6:27). He then continued by talking about the true bread from Heaven the bread of God, and the bread of life. (John 6:32-35). Here He appeals to the soul for its nourishment and our thoughts to the spiritual way so as not to occupy our minds with the body and its needs.
When Christ said that “Man shall not live by bread alone.” (Matt 4:4), He meant by this, that man should not live solely to nourish his body with bread and forget the nourishment of the soul. This is also clear when He said to His disciples: “I have food to eat of which you do not know." (John 4:32)