1. Question Restatement
Did Jesus promise literal food and clothing in Matthew 6:33 - by commanding not to worry about food and clothing?
2. Applies literally - to a very peculiar kingdom of only priests :
Jesus expected this commandment to be obeyed, somehow :
NASB, Matthew 28:19-20 - Go ... make disciples ... 20 teaching them to observe all that I commanded you;
None of Jesus' commandments are "superficial only".
Jesus commands are NOT "Don't worry, be happy" (Bobby McFerrin).
Even "Love" comes with an action: "Love [unconditionally] as I have loved you, (John 15:12). Further, Jesus' literal explanation of the commandment would mean absolutely nothing - and wastes space on the page : where he reasoned that if God cares for even the birds, then how much more will he care for his people?
This commandment certainly requires trust (i.e., maturity in the Spirit), or at the very least "Dispensational" in an Eschatological sense :
NASB, Exodus 19:6 - and you shall be to Me a kingdom of priests and a holy nation.’ These are the words that you shall speak to the sons of Israel.”
NASB, Numbers 35:2 - 2 ... give to the Levites from the inheritance of their possession cities to live in; and you shall give to the Levites pasture lands around the cities.
NASB, Deuteronomy 18:2 - [The Priests] shall have no inheritance among their countrymen; the Lord is their inheritance, as He promised them.
NASB, Psalm 37:25 - I have been young, and now am old; Yet I have not seen the righteous forsaken, Nor his descendants begging bread.
NASB, Revelation 1:6 - ... and He has made us to be a kingdom, priests to His God and Father ... (See also Titus 2:14, 1 Peter 2:9)
Jesus argues that commandments should NOT be made of no effect, through traditional interpretations that they are "metaphorical", and can be observed "in heart only", (See Matthew 15:6).
I think Solomon would says that commandments are intended for all people, perhaps according to their maturity :
NASB, Ecclesiastes 12:13 - The conclusion, when all has been heard, is: fear God and keep His commandments, because this applies to every person.
3. Disclaimer - No "Blind Leaps of Faith", in Scripture :
Please don't interpret this in the extreme, (like when people hear that word for "sorcery" is the same as "pharmacy" - in Galatians 5:20, Interlinear).
If faith is trusting the Word of God - through experience, and someone doesn't have this experience, then one should exercise an abundance of caution, making so-called "leaps of faith", because :
NASB, Romans 14:23 - and whatever is not from faith is sin.
NASB, Galatians 4:19 - My children [who are Christians], with whom I am again in labor until Christ is formed in you
New Testament texts very clearly delineate Christians according to the measure of their faith, (Search for "Faith" in Romans 12), between "young Christians", and the "Mature" who have experienced the trustworthiness of God : those who can walk according to this commandment, by faith. (See also example of people trusting in God, because of his trustworthiness, in Hebrews 11, especially Hebrews 11:11.)