Jesus' audience in this passage in Israel. Matthew 6:25-33 is the parallel passage to this one.
(Matthew 6:32 KJV) (For after all these things do the Gentiles seek:) for your heavenly Father knoweth that ye have need of all these things.
(Matthew 6:33 KJV) But seek ye first the kingdom of God [seek entry into the kingdom of God], and his righteousness [his pardoning]; and all these things shall be added unto you.
(Matthew 6:34 KJV) Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day is the evil thereof.
Jesus here is teaching against materialism and covetousness, as well as teaching them how to be Christ-like [Matthew 6:33; Luke 12:33-34]. If your heart is on earthly things then that goes against other scripture like Colossians 3:1-2.
(Colossians 3:1 KJV) If ye then be risen with Christ, seek those things which are above, where Christ sitteth on the right hand of God.
(Colossians 3:2 KJV) Set your affection on things above, not on things on the earth.
I would rather call it a universal instruction rather than a commandment. It is true, of those in every dispensation, that if we do good deeds out of a true heart then we will be rewarded with heavenly treasures, an inheritance [Luke 12:33; 2 Timothy 2:12; Ephesians 5:5].
The larger point of the passage actually seems to be prioritizing faith.
(Hebrews 11:6 KJV) But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
Habakkuk 2:4 (KJV) Behold, his soul which is lifted up is not upright in him: but the just shall live by his faith.
Romans 1:17 (KJV) For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith.
Galatians 3:11 (KJV) But that no man is justified by the law in the sight of God, it is evident: for, The just shall live by faith.
Hebrews 10:38 (KJV) Now the just shall live by faith: but if any man draw back, my soul shall have no pleasure in him.
Addendum: As Jesus has stressed many times, it is better to live in drastic circumstances (sell all that ye have and give alms) or to sustain drastic injury on earth (maim yourself) than to be whole and not enter into the eternal life. Therefore I don't say this verse is a commandment, but an instruction.