isaiah 32:20 Blessed are ye that sow beside all waters, that send forth thither the feet of the ox and the ass. - Free Bible Online

      20. While the enemy shall be brought "low," the Jews shall cultivate their land in undisturbed prosperity.
      all waters--well-watered places (Isa 30:25). The Hebrew translation, "beside," ought rather to be translated, "upon" (Ec 11:1), where the meaning is, "Cast thy seed upon the waters when the river overflows its banks; the seed will sink into the mud and will spring up when the waters subside, and you will find it after many days in a rich harvest." Before sowing, they send oxen, &c., into the water to tread the ground for sowing. CASTALIO thinks there is an allusion to the Mosaic precept, not to plough with an ox and ass together, mystically implying that the Jew was to have no intercourse with Gentiles; the Gospel abolishes this distinction (Col 3:11); thus the sense here is, Blessed are ye that sow the gospel seed without distinction of race in the teachers or the taught. But there is no need of supposing that the ox and ass here are yoked together; they are probably "sent forth" separately, as in Isa 30:24.

JFB.