Verse 1
"To the chief Musician, A Psalm for the sons of Korah"
To the chief Musician — the leader of the Levite singers in the Temple; the sons of Korah — a family of Levite poets. That is: the heading, naming who composed and sang the psalm.
In one line: a song of the singers of the house itself.
Verse 9
"I will hear what God the LORD will speak: for he will speak peace to his people, and to his saints: but let them not turn again to folly"
I will hear — I will listen in silence; his saints — those faithful to him; folly — the false confidence that led to exile. That is: the singer stops asking and listens, and he hears peace, if the people do not return to folly.
In one line: be still and listen, and you will hear peace.
Verse 10
"Surely his salvation is near them that fear him; that glory may dwell in our land"
Surely — certainly; them that fear him — those who stand in awe of him; glory may dwell — God's presence may live again in the land. That is: salvation is close, and its purpose is that his presence returns here.
In one line: salvation is near, and glory comes home.
Verse 11
"Mercy and truth are met together; righteousness and peace have kissed each other"
Mercy — goodness given freely; truth — what is right and steady; met together — like two travellers from different roads; have kissed — embraced and became one. That is: four qualities that usually pull apart meet here and unite.
In one line: what is usually apart meets here and embraces.
Verse 12
"Truth shall spring out of the earth; and righteousness shall look down from heaven"
Spring out of the earth — rise from the soil like a sprout; look down from heaven — gaze from above, as from a window. That is: the mending comes from both directions at once and meets in the middle.
In one line: truth rises from the earth, righteousness looks down from heaven.
Verse 13
"Yea, the LORD shall give that which is good; and our land shall yield her increase"
Yea — yes, and on top of all this; that which is good — the rain and blessing; yield her increase — bring forth her harvest. That is: when heaven gives, the earth gives too, and blessing becomes bread.
In one line: the LORD gives from above, and the land gives from below.
Verse 14
"Righteousness shall go before him; and shall set us in the way of his steps"
Go before him — walk ahead like a herald; set us in the way of his steps — make a path for us to follow his footsteps. That is: righteousness walks before the LORD and marks the road we follow.
In one line: righteousness leads, and marks the way for us.
The first part asked how long; the second answers with one word, peace.