Question: In the Book of Daniel, the Prophecy of Seventy Weeks, is given to Daniel by which angel, who typically serves as God's messenger, in response to Daniel, praying for God to act on behalf of his people and city of Jerusalem?

Context paragraphs:
New Jerusalem: In the Book of Ezekiel in the Hebrew Bible, New Jerusalem (, "Jehovah-shammah", or "[where] YHWH [is] there") is Ezekiel's prophetic vision of a city centered on the rebuilt Holy Temple, the Third Temple, to be established in Jerusalem, which would be the capital of the Messianic Kingdom, the meeting place of the twelve tribes of Israel, during the Messianic era.  The prophecy is recorded by Ezekiel as having been received on Yom Kippur of the year 3372 of the Hebrew calendar.  It will be inhabited by people to live eternally in spirit form, created by God as a gift to mankind.  Not everyone will reside in New Jerusalem, as most will possibly stay on Earth.

Gabriel: Gabriel ( "Gavri'el" "God is my strength", Biblical Greek: Γαβριήλ, "Gabriel"; Amharic, Geez and Tigrinya: ገብርኤል, Arabic: جبريل or جبرائيل "Jibril" or "Jibra'il"), in the Abrahamic religions, is an angel who typically serves as God's messenger.

Polybus of Corinth: Polybus (Greek: Πόλυβος ) is a figure in Greek mythology.  He was the king of Corinth and husband of either Merope or Periboea.  He raised Oedipus as his adopted son, who had been abandoned by his parents Laius and Jocasta of Thebes in Greece.  Polybus was the true father of Alcinoe.  In virtually all accounts of the mythology, when Oedipus reached adolescence, he consulted with the Delphic Oracle, who told him "You shall kill your father and marry your mother".  Obviously horrified and disgusted with such a prophecy, Oedipus imposed self-exile upon himself and kept away from Corinth, as he resolved never to murder King Polybus, who had been a kind father to him.  Oedipus was also understandably disgusted the act of murdering Polybus and claiming his wife for himself, as he had no unnatural attraction to Queen Merope.  Many years later, after Oedipus won the kingship of Thebes by defeating the Sphinx, did another plague befall Thebes.  King Oedipus, in his effort to find the cause of plague due to a patricide, revealed that he was told in his teen years that he was destined to murder his father, and sent a spy to Corinth to see who is currently on the throne.  The news of Polybus' death by natural causes was announced by the messenger to Jocasta in Sophocles' "Oedipus Rex", in which it is mistakenly taken to mean that Oedipus did not kill his father.  This would mean that the prophecy that Oedipus would murder his father and marry his mother would be false, and Oedipus expresses relief that he did not commit such a heinous act.  Since Polybus was in fact his adoptive father, Oedipus could and did kill his true father, King Laius, and fulfill the prophecy.  Oedipus never knew his true destiny until the final parts of the play.

Daniel (biblical figure): Daniel (, Hebrew "God is my Judge") is the hero of the Book of Daniel.  A noble Jewish youth of Jerusalem, he is taken into captivity by Nebuchadnezzar of Babylon and serves the king and his successors with loyalty and ability until the time of the Persian conqueror Cyrus, all the while remaining true to the God of Israel.  Some conservative scholars continue to argue that Daniel was a genuine individual and that the book that bears his name reflects real history, but the broad consensus is that Daniel never existed and that the book is a cryptic allusion to the reign of the 2nd century BCE Greek king Antiochus IV Epiphanes.

Hadith of Jesus Praying Behind Mahdi: Hadith of Jesus Praying Behind Mahdi (Persian: حدیث نماز خواندن عیسی به امامت مهدی‎ ‎ ) refers to a collection of hadith related about the prophecy that Jesus will follow Mahdi's lead in "salat" (prayer) after he descends.  Mahdi is the twelfth Imam of the Shia muslims and salat is the Islamic practice of worship of God which muslims perform five times a day.  The prophecy is narrated in numerous hadith collections.  A total of 29 Hadiths relate the return of Jesus, and his prayer with Mahdi's lead.

Daniel 2: Daniel 2 (the second chapter of the Book of Daniel) tells how Daniel interpreted a dream of Nebuchadnezzar, king of Babylon.  The king saw a gigantic statue made of four metals, from its gold head to its feet of mingled iron and clay; as he watched, a stone "not cut by human hands" destroyed the statue and became a mountain filling the whole world.  Daniel explained to the king that the statue represented four successive kingdoms beginning with Babylon, while the stone and mountain signified a kingdom established by God which would never be destroyed nor given to another people.  (The dream and its interpretation are given in verses 31-45).  Nebuchadnezzar then acknowledges the supremacy of Daniel's God and raises him to high office in Babylon.

Prophecy of Seventy Weeks: In the Book of Daniel, the Prophecy of Seventy Weeks is a prophecy given to Daniel by the angel Gabriel in response to Daniel praying for God to act on behalf of his people and city (i.e. Jerusalem).  The prophecy has proved notoriously difficult for readers, despite it having been the subject of "intense exegetical activity" since the Second Temple period.  For this reason scholars continue to follow James Alan Montgomery in referring to the history of this prophecy's interpretation as the "dismal swamp" of critical exegesis.

Daniel in the lions' den: The story of Daniel in the lions' den (chapter 6 in the Book of Daniel) tells how Daniel is raised to high office by his royal master Darius the Mede, but jealous rivals trick Darius into issuing a decree which condemns Daniel to death.  Hoping for Daniel's deliverance, but unable to save him, the king has him cast into the pit of lions.  At daybreak he hurries back, asking if God had saved his friend.  Daniel replies that God had sent an angel to close the jaws of the lions, "because I was found blameless before him."  The king has those who had conspired against Daniel, and their wives and children, thrown to the lions in his place, and commands to all the people of the whole world to "tremble and fear before the God of Daniel".

Prayer walk: A prayer walk is an activity that consists in walking and praying at the same time.  It's done not for the physical benefit but for the spiritual exercise, either publicly functioning also as a demonstration or rally (to let other people know the group is praying), or quietly in sight of the subject.  For instance, a person or group may be praying for a town or city, and walk the streets of the city while praying, either out loud, or in silence.

Belshazzar's feast: Belshazzar's feast, or the story of the writing on the wall (chapter 5 in the Book of Daniel) tells how Belshazzar holds a great feast and drinks from the vessels that had been looted in the destruction of the First Temple.  A hand appears and writes on the wall.  The terrified Belshazzar calls for his wise men, but they are unable to read the writing.  The queen advises him to send for Daniel, renowned for his wisdom.  Daniel reminds Belshazzar that his father Nebuchadnezzar, when he became arrogant, was thrown down until he learned that God has sovereignty over the kingdom of men.  Belshazzar had likewise blasphemed God, and so God sent this hand.  Daniel then reads the message and interprets it: God has numbered Belshazzar's days, he has been weighed and found wanting, and his kingdom will be given to the Medes and the Persians.

Supporting paragraphs: Prophecy of Seventy Weeks Gabriel
Answer: Gabriel