How were we chased on our necks?
Rashi: A yoke of harsh work is on our necks.
Ibn Ezra: If we bring water or wood on our necks, the enemy chased us [and took them]. Our toil was for naught, since they did not let us keep what we brought!
Ri Kara: They imposed their yoke on our necks and took the money for which we toiled. Hunach with a Dagesh 1 in the Nun is an expression of leaving; they did not leave our money with us. If it did not have a Dagesh, it would be an expression of resting.
Rid: We bear their burdens on our necks, and they chase us!
Minchas Shai: Accurate txts have a Dagesh.
What is the meaning of "Yagznu v'Lo Hunach Lanu"?
Rashi: We toiled to gather money and property, and our toil did not stay in our hand. The enemies collect and grab everything via taxes, head-taxes and tithes.
Refer to 5:5:1:2-3.