‘The nations are sunk down in the pit that they have made,
In the net which they concealed is their own foot taken.
YHWH has made himself known, he has executed judgment:
The wicked is snared in the work of his own hands. Higgaion. Selah
The consequence is that, thanks to God, those who have raised themselves against him have been defeated. They have set their traps for him and now they have fallen into their own traps. They have laid their hidden nets and now they have been caught in them themselves. Note how these descriptions stress their unrighteousness, because in the end the whole message of the Psalm is about the battle between righteousness and unrighteousness, with righteousness finally being the victor through the power of the Righteous One. Israel, the chosen of YHWH, is to be blessed because in as far as she is righteous. The nations are to be judged because they are unrighteous. On the one hand YHWH has made Himself known on behalf of the righteous, executed judgment and gained the victory, and on the other the unrighteous have been caught in their own snares. (Once Israel proved herself consistently unrighteous she lost the protection and the blessing).
So these words can still be applied to the true people of God, the new Israel, (Galatians 3:29; Galatians 6:16; Ephesians 2:12-22; Romans 11:17-24) today. They live as righteous ones in an unrighteous world, and can be sure of God's genuine concern and action on their behalf.
‘Higgaion. Selah.' Higgaion is a call for musical instruments to play (compare Psalms 92:3 where it refers to the sound of a stringed instrument) in order to emphasise the triumphant conclusion. Selah may indicate a moment of pause, possibly while only music is played, signifying ‘think of what you have heard' or ‘rejoice in what you have heard'.