A treatise concerning marriage : wherein the unlawfulness of mixt mariages [as printed] is laid open from the scriptures of truth: shewing that it is contrary to the will of God, and the practice of his people in former ages, and therefore of dangerous consequence, for persons of different judgments, in matters of religious worship, to be joyned together in marriage. : Written for the information and benefit of Christian professors in general; and recommended more particularly to the youth of either sex amongst the people called Quakers. /