The Letter to the Hebrews
The author of Hebrews is anonymous, and the recipients of the letter are also anonymous. However, it is certain from the theme of the entire letter, beginning in Heb 1:1, that both the author and the recipients are Jewish. Heb 13:24 says "all the saints from Italy greet you." This probably means that the author is not in Italy, but some Italians are with him, and he is sending a letter to Italy. It would be most natural to assume that this letter was written to a Jewish congregation of believers living in Italy, probably in Rome. The only biographical reference in the letter is to "our brother Timothy" in Heb 13:23. Despite the fact that the author is unknown to us, he is known to the recipients of the letter (Heb 13:22).
More than any other book in the New Testament, Hebrews reads as a book written prior to the destruction of Jerusalem in 70 A.D. Heb 5:1-4 says “For every high priest taken from among men is appointed on behalf of men in things pertaining to God, in order to offer both gifts and sacrifices for sins; he can deal gently with the ignorant and misguided, since he himself also is beset with weakness; and because of it he is obligated to offer sacrifices for sins, as for the people, so also for himself. And no one takes the honor to himself, but receives it when he is called by God, even as Aaron was.” This passage about what high priests do is set entirely in the present tense, something that would be overcome by events if the book was written after 70. Heb 9:25 says “the high priest enters the holy place year by year with blood that is not his own.” Heb 10:11 says “Every priest stands daily ministering and offering time after time the same sacrifices, which can never take away sins.” Again, both passages are set in the present tense. Furthermore, Hebrews is making a case that the sacrifices before Christ were insufficient. If the writer knew of the destruction of the Temple, the altar, and the entire sacrificial system, he could have used these events to bolster his argument, saying “see, they have passed away in any case.” The reason he doesn’t do this is probably because when he wrote Hebrews, these things had not yet happened.
Hebrews warns more severely against apostasy than any other book in the New Testament. Heb 6:4-6 says "For in the case of those who have once been enlightened and have tasted of the heavenly gift and have been made partakers of the Holy Spirit, and have tasted the good word of God and the powers of the age to come, and then have fallen away, it is impossible to renew them again to repentance, since they again crucify to themselves the Son of God and put Him to open shame." Similar sharp warnings occur in 12:15-29 and especially 10:26-31. Apparently the temptation to deny the faith was exceptional at the time the letter was written. If the recipients were in Rome, the plausible setting would be during the persecution of Roman Christians under Nero. This occurred after the burning of Rome on July 18-19 of 64 A.D., an event Nero blamed on the Christians. This would place Hebrews after the end of the account in Acts, and after all of Paul's letters. Since Heb 13:23 says Timothy was now out of prison, and none of the other books in the New Testament have him in prison, this also implies that the book was written after Paul and Acts.
These facts combine to create a window of time for the dating of Hebrews, set after the burning of Rome in 64 but before the destruction of Jerusalem in 70. There is also no allusion at all in Hebrews to the Jewish Roman war, which started in 66 A.D. Since some time should be allowed for the crisis in Rome to develop and to prompt this letter, yet allow the war to go unmentioned, Hebrews should be dated around 66 A.D.