Psalms 49:3

My mouth shall speak of wisdom; and the meditation of my heart shall be of understanding.

The call in the psalm is addressed to the whole world, requiring all the inhabitants of the earth to give ear and listen.
The one who speaks is Christ, and His promise to speak wisdom means that He Himself is Wisdom.
The meditation of the heart is inward thought aimed at understanding, formed by reflecting upon the things of the Lord.

The psalm as a whole inculcates the necessity of trusting in God.
The wisdom uttered declares the emptiness of riches and their utter inability to ransom a soul.
That same wisdom lays bare the folly and culpability of wicked self-reliance.
It announces the coming morning when the righteous shall have dominion over the wicked and be redeemed from the power of the grave in the first resurrection to live and reign with Christ.