John 7:35 has Jews speculating that Jesus might go teach the Greeks — now in 12:20, Greeks actually come seeking him, fulfilling that hint.

In 1 Kings 8:41-43, Solomon prays for foreigners who come to the temple, fulfilled when Greeks come to worship.

Isaiah 11:10 prophesies that the Root of Jesse will be a banner for the nations, whom the Gentiles will seek—fulfilled in the Greeks coming to Jesus in John 12:20.

2 Chronicles 6:32 records Solomon's prayer that God would hear foreigners who come to worship at the temple—anticipating the very situation of Greeks seeking Jesus.

Isaiah 56:7 declares that God's house will be a house of prayer for all nations, directly predicting the inclusion of Gentiles like the Greeks in John 12:20.

Isaiah 60:3 prophesies that nations will come to Jerusalem's light, a promise being realized as the Greeks approach Jesus, the light of the world.

Acts 16:14 introduces Lydia, a Gentile worshiper of God—an example of a Gentile seeking God, similar to the Greeks in John 12:20, but a different event.