Clement of Rome wrote to the church in Corinth around AD 90. This is perhaps the same Clement, companion of Paul, mentioned in Philippians 4:3. Many hold him to be the first bishop / pope in Rome, aka St. Clement I.
Clement quotes from the letter to the Hebrews. Origin suggested that Clement was in fact the writer (as transcriber or amanuensis) of Hebrews. Perhaps this letter began as a "word of exhortation" given by Paul at the synagogue (Heb 13:22; cf Acts 13:15) which then became a circular letter for the churches. Other possible authors of Hebrews include Luke, Barnabas, or Apollos. The theology is Pauline, but the transcriber is obviously second-generation (Heb. 2:3-4).
At any rate, this early church leader in Rome, is already quoting Hebrews in his letter in AD 90:
CHAPTER 36 ALL BLESSINGS ARE GIVEN TO US THROUGH CHRIST
This is the way, beloved, in which we find our Savior, even Jesus Christ, the High Priest of all our offerings, the defender and helper of our infirmity. By Him we look up to the heights of heaven. By Him we behold, as in a glass, His immaculate and most excellent visage. By Him are the eyes of our hearts opened. By Him our foolish and darkened understanding blossoms up anew towards His marvelous light. By Him the Lord has willed that we should taste of immortal knowledge, “who, being the brightness of His majesty, is by so much greater than the angels, as He hath by inheritance obtained a more excellent name than they.” For it is thus written, “Who maketh His angels spirits, and His ministers a flame of fire.” But concerning His Son the Lord spoke thus: “Thou art my Son, today have I begotten Thee. Ask of Me, and I will give Thee the heathen for Thine inheritance, and the uttermost parts of the earth for Thy possession.” And again He saith to Him, “Sit Thou at My right hand, until I make Thine enemies Thy footstool.” But who are His enemies? All the wicked, and those who set themselves to oppose the will of God.