The answer is: Psalm 2

Acts 13:33 - Paul's quotation from Psalm 2 highlights Jesus as God's anointed king. This psalm underscores the sovereignty of God and the futility of earthly rulers opposing divine plans. The New Testament frequently links Christ to psalmic prophecy, echoing themes of authority and kingship found in Isaiah and Revelation as well.

In his exhortation at Antioch, Paul effectively shows the deeper connections found in the Psalms, particularly Psalm 2. This psalm offers a rich tapestry of understanding God's power and purpose in history, portraying both His sovereign authority and the cosmic resistance to it. This age-old struggle reflects the principal theme of rebellion, as human figures seek to overthrow divine plans—an echo found throughout Scripture.

Interestingly, Psalm 2 traditionally celebrates the coronation of a king in ancient Israel. This gave it a dual significance in the early Christian context: It didn't just refer to the kings of the past but is also seen as foreshadowing Jesus' role. By quoting this psalm, Paul positions Jesus as the ultimate fulfillment of God's plan, anointed not just as a king but the Messiah, chosen to lead all of humanity.

Moreover, Psalm 2 is fascinating in its imagery of "the nations raging" and rulers conspiring. It had a profound resonance during the time of the early church, facing persecution. This psalm and Paul's reference would serve as challenges, an encouragement to hold fast in trials, reminding believers of the ultimate triumph of the divine.

Timeline-wise, Solomon is also thought to be a descendent imbued with 'kingly authority,' as reflected not only in Psalms but reverberated through biblical history. Hence, this quotation serves not just as doctrinal evidence but provides audience-context solidifying Jesus' legitimacy in a worldview craving hope and governance from divine providence.