Publication refers to the sharing  of God's word with others.  One can publish something by copying it  to reproduce it and distribute it or by  verbally pronouncing it.

This can even be done simply through living  life in a Godly way.  To publish something is another way of saying to proclaim or to preach  as well.

Psa. 68:11

[11] The Lord gave the word: great was the company of those that published it.

2 Cor.3:2-3

[2] Ye are our epistle written in our hearts, known and read of all men:
[3] Forasmuch as ye are manifestly declared to be the epistle of Christ ministered by us, written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshy tables of the heart.

Isa. 52:7

[7] How beautiful upon the mountains are the feet of him that bringeth good tidings, that publisheth peace; that bringeth good tidings of good, that publisheth salvation; that saith unto Zion, Thy God reigneth!

Rom. 10:8-15

[8] But what saith it? The word is nigh thee, even in thy mouth, and in thy heart: that is, the word of faith, which we preach;
[9] That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
[10] For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
[11] For the scripture saith, Whosoever believeth on him shall not be ashamed.
[12] For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him.
[13] For whosoever shall call upon the name of the Lord shall be saved.
[14] How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?
[15] And how shall they preach, except they be sent? as it is written, How beautiful are the feet of them that preach the gospel of peace, and bring glad tidings of good things!

You have received God's truth freely  freely share it with others.