The above saying is a common one; but, as I've realized, popularity does not always equal understanding. Perhaps it's a bit of over familiarity that comes into play when we hear those words from the scripture (Deuteronomy 8:3, Matthew 4:4).

In my Bible study today, with God's insight, I've realized [one of] the meaning(s) of those words from scripture. It's easy to focus on your physical self and neglect your spiritual well-being. When you're hungry, you eat. When you're sick, you go to the hospital. But it's not always so clear cut with our spiritual lives. Some people feel the need to pray more, or read the Bible more but choose to ignore it. Probably because the feeling is not physical and it's relatively easier to ignore. It's not as conspicuous as hunger pangs so you wave it aside.

But this verse is saying; Don't only focus on feeding your physical self. Treat your spiritual life as important, even more so than your physical self. Spend time with God in prayer, Read his word, Meditate on his word, Learn more about him from teachers; these could include pastors, ministers, Bible-believing Christian websites, Christian devotionals, Christian videos and so on. How you draw close to God is particular to your relationship with him.

Finally, do make sure to apply his word to your life. As Galatians 5:25 says: "Since this is the kind of life we have chosen, the life of the Spirit, let us make sure that we do not just hold it as an idea in our heads or a sentiment in our hearts, but work out its implications in every detail of our lives". {The Message Bible}