Maybe this isn't new to some of you, but I've recently come across a fascinating interpretation of Psalm 24
Psalm 24
1 The earth is the Lord's, and the fulness thereof; the world, and they that dwell therein.
2 For he hath founded it upon the seas, and established it upon the floods.
3 Who shall ascend into the hill of the Lord? or who shall stand in his holy place?
4 He that hath clean hands, and a pure heart; who hath not lifted up his soul unto vanity, nor sworn deceitfully.
5 He shall receive the blessing from the Lord, and righteousness from the God of his salvation.
6 This is the generation of them that seek him, that seek thy face, O Jacob. Selah.
7 Lift up your heads, O ye gates; and be ye lift up, ye everlasting doors; and the King of glory shall come in.
8 Who is this King of glory? The Lord strong and mighty, the Lord mighty in battle.
9 Lift up your heads, O ye gates; even lift them up, ye everlasting doors; and the King of glory shall come in.
10 Who is this King of glory? The Lord of hosts, he is the King of glory. Selah.
I think it's rather agreed upon that this is a Messianic Psalm, and while there is much to chew on, I want to highlight the latter half.
What I've found throughout most of what I've been taught about this Psalm is that the "gates" here are typically a reference to heavenly gates, and the Psalm is referring to Christ's ascension. Or perhaps it's symbolic of Christ entering Jerusalem (after all, that's the hill of the Lord).
I don't think we can fully discount those interpretations but it seems in the surrounding pagan nations of the time there was a similar reference to 'everlasting doors' or gates as meaning gates, not to heaven, but to the underworld. To Hades/Sheol. As well as a tradition of venturing into the underworld passing gates and the gatekeepers who would question them. So in some ways this can be seen as a polemical psalm, poking pagan nations in the eye. But also a prophetic psalm, looking to Christ's victorious descent into Hades.
Upon his death, Christ, who said the gates of Hell shall not prevail against His church, ventured into the underworld and this scene the psalm speaks of plays out as an exchange between Christ and the Gatekeepers of Hell. Lift them gates. The King of Glory has come. Who is this King of Glory? The Lord. He's mighty in battle and he will come in, take the keys of Death and Hades, proclaim his victory to the evil spirits in prison, and then lead a host of captives (the righteous dead, and, as it were, all believers) out of Hades.
We don't quite need Psalm 24 in order to believe that happened, but I think the possibility that the 'gates' are the gates of Hades is extremely interesting.