Psalm 126
v.1
When the Lord brought back the captives to Zion, we were like men who dreamed.
The Latin Vulgate and the Septuagint render this, “we were comforted.” The meaning is, “It seemed like a dream; we could hardly realize that it was so; it was so marvelous, so good, so full of joy, that we could scarcely believe it was real.” This state of mind is not uncommon, when, in sudden and overpowering joy, we ask whether it can be real; whether it is not all a dream. We fear that it is; we apprehend that it will all vanish away like a dream.
v.2
Our mouths were filled with laughter, our tongues with songs of joy. Then it was said among the nations, “The Lord has done great things for them.”
v.3
The Lord has done great things for us, and we are filled with joy.
v.5
Those who sow in tears will reap with songs of joy.
v.6
He who goes out weeping carrying seed to sow, will return with songs of joy, carrying sheaves with him.
See more context in Barnes on Psalm 126 6 Psalm126 v 6.