John Wesley on Jeremiah 31:9

With weeping - Some think that it had been better translated, they went weeping; for though the verb be the future tense in the Hebrew, yet that tense has often the signification of the preterperfect tense, thus it answereth, Psa 126:5,6. He that goeth forth weeping, bearing precious seed, shalt doubtless come again rejoicing. There is a weeping for joy, as well as for sorrow, and thus the text corresponds with that, Zech 12:10. I will pour upon them the spirit of grace and supplications, and they shall look upon him whom they have pierced, and mourn. By rivers - And they shall have no want as they had when they came out of Egypt, through the wilderness, where they often wanted water.