The first pronunciation with the stress on the first syllable is older and regarded by some as the only correct one, but the second pronunciation with the stress on the second syllable is now also frequently encountered.
For it is a stout calf, ripe for the temples and altar [to be sacrificed], and to be sprinkled with wine; who is now ashamed to draw the dugs of his mother, and who harasseth the oaks with his budding horn.
In my old home, I always knew that John and my master were my friends; but here, although in many ways I was well treated, I had no friend. York might have known, and very likely did know, how that rein harassed me; but I suppose he took it as a matter of course that could not be helped; at any rate nothing was done to relieve me.
Some who dwell in wildernesses, / who seek and occupy, by their own wills, homes in dark caverns, these await / the heavenly dwelling-place; he who grudgeth them life, / oft bringeth hateful terror upon them; / sometimes he showeth them horror, sometimes vain glory; / the wily murderer hath power of both, / and harasseth these lonely-dwellers; […]
A modern English translation of a 10th-century Old English text.
To harass good people is no different than speaking ill of them.
1761, Thomas Boston, “State II. Namely, the State of Nature or of Entire Depravation. Head I. The Sinfulness of Man’s Natural State. [Of the Corruption of the Will.]”, in Human Nature in Its Four-fold State[…], 12th edition, Edinburgh: […] David Gray[…], OCLC1227576333, page 80:
The ſoul that dies this death, is like a loving wife matched with a rigorous huſband: ſhe does what ſhe can to pleaſe him, yet he is never pleaſed; but toſſeth, haraſſeth, and beats her, till ſhe break her heart, and death ſets her free: […]
Zeal without judgment is an evil, though it be zeal unto good; / […] / By a shoulder to the wheel downhill harasseth the labouring beast, / And where an obstruction were needed, will harm by an ill judged thrusting-on.
But meanevvhile, to harraſſe and vvearie the Engliſh, they [the French] did vpon all aduantages ſet vpon them vvith their Light-Horſe; vvherein neuertheleſſe they receiued commonly loſſe, eſpecially by meanes of the Engliſh-Archers.
1712 March 4 (date written; Gregorian calendar), J[onathan] Swift, A Proposal for Correcting, Improving and Ascertaining the English Tongue;[…], 2nd edition, London: […] Benj[amin] Tooke,[…], published 1712, OCLC1102741209, page 9:
[T]he Britains, left to ſhift for themſelves, and daily haraſſed by cruel Inroads from the Picts, were forced to call in the Saxons for their Defence; […]
VVhich Troupes came to the Army but the day before, harraſed vvith a long and vveariſome march: and (as it is left for a memorable circumſtance in all Stories,) the Souldiers, being more ſenſible of a little Heat of the Sunne, than of any cold Feare of Death, caſt avvay their Armour, and Garments from them, and fought in their Shirts: […]
Nature oppreſs'd, and harraſs'd out with Care, / Sinks down to Reſt.
1812, John Mason Good, “Part II. First Series of Controversy.”, in The Book of Job, Literally Translated from the Original Hebrew, and Restored to Its Natural Arrangement:[…], London: […] [F]or Black, Parry, and Co.[…], by R. Watts, Broxbourn Press, OCLC1190975254, JobXIV:19–20:
As the waters wear to pieces the stones, / As their overflowings sweep the soil from the land,— / So consumest thou the hope of man; / Thou harassest him continually till he perish; / Thou weariest out his frame, and despatchest him.
'[T]is true, that he neither harasseth his vassals from morn to eve by hard labour and exaction, nor committeth them to the dungeon, when they can no longer work nor pay. But to knights of our calling, Monsieur Robichon, he is as ill disposed as the worst of them:— […]
Now, Belford, if ſhe be not much concerned at the broken veſſel, which, in one ſo fiery in his temper as I have the reputation to be thought, may be very dangerous; a malady that I ſhall calmly attribute to the haraſſes and doubts, that I have laboured under for ſome time paſt; which will be a further proof of my love, and will demand a grateful return—