Psalm 126 features a hope of ascent sufficient to endure trials of destitution and exile.  This is a song fitting for the covenantal terms prophetically revealed by Moses in Dt 4: 25-31. Here the prophet, declares before witnesses that the consequences of apostasy for Israel would include defeat, exile, & persecution…yet God would not utterly banish His covenant people forever.  There was hope for restoration of the covenant and its land upon repentance & revival. Consider the frame of mind maintained in exile by the author and those who joined him in his hope for Zion.  These 'far from home' worshippers would realize their greatest dreams fulfilled upon return from captivity.  As they returned to Zion at the appointed time, their seeds of prayer, anguished longing, & remembrance would spring forth from the ground reaping fruits of surpassing joy.