The book of Hebrews says The Gospel was preached to the Children of Israel after they came out of Egypt.
That is the unmistakable message of Hebrews 4:2 and the verses leading up to Hebrews 4:2
The Gospel is always going to be whatever YHVH God the Father says to DO.
Everything YHVH God the Father says to DO is The Way to Him and His Kingdom and that is very good news.
The Commandments are the unchangeable instructions of how we are to live and obey God our Father. The Commandments are not optional in any way, shape, or form.
The Commandments, the statutes, and the ordinances and all God our Father says are the good news that if we DO those things then we are found in good standing with Him at The Judgment. God our Father refers to all these things as His Torah or THE LAW He gave to the Children of Israel.
John 10:35 says The Scripture cannot be broken and that means from the beginning to the end The Scripture is without change.
Most say Paul was the writer of Hebrews. Some say it was Luke. Others have suggested Apollos, Barnabas, and Priscilla.
Maybe they all had a hand in writing Hebrews as verse 4:2 refers to “US”.
Hebrews verse 4:2 says “the Gospel was preached to US”
And Hebrews verse 4:2 says the very same Gospel preached to Paul, Luke, Apollos, Barnabas, Priscilla, Peter, James, and all the others who followed God’s Son was also preached to those Children of Israel who came out of Egypt.
Make no mistake about it The Gospel was preached in Exodus, Leviticus, Numbers, and Deuteronomy.
The Gospel is The Word of YHVH which no man can live without.
The Gospel is whatever God our Father says we are to DO to serve Him.
God’s Son lived The Gospel.
And since The Gospel = THE LAW of YHVH, God’s Son died because he kept THE LAW perfectly and the false religious leaders of Judaism hated him and killed him.
Both Paul and Peter say to obey The Gospel.
Remember to keep the Sabbath Holy and keep all THE LAW of YHVH. That is Isaiah 56.