This phrase in Isaiah has given commentators considerable trouble. "Hear ye ... which are come forth out of the waters of Judah." What can the "waters of Judah" mean? Some read, "From the bowels of Judah"; others, "From the fountains of Jacob"; others, "From the days of Judah." From "the waters of baptism" is the true meaning. Whether this simple and obvious explanation came from the prophet Isaiah himself and had been engraved on the plates of Laban; or whether they are a gloss inserted by the prophet Nephi in his copy of the text, does not matter. In either case, it is an inspired explanation of an admittedly difficult passage.
Baptism was by no means unknown among the Jews at the time of Isaiah. When Jacob, returning from Haran, was about to re-enter the land of Canaan and build an altar to Jehovah at Bethel, he called his household together and said to them, "Put away the strange gods that are among you, and be clean, and change your garments." (2 Kings 5:14, where we read that Naaman, after having dipped himself in the Jordan, according to the word of the Lord, was cured of leprosy, "and he was clean." He was cleansed, not only of his sickness but of the contamination of paganism, for he exclaimed, "Behold, now I know that there is no God in all the earth, but in Israel." In other words, he was a new man, spiritually as well as physically.
From the Writings of Moses in the Pearl of Great Price we know that Adam was baptized. And when he had received the Holy Spirit, he heard a voice out of heaven, saying: "Thou art baptized with fire, and with the Holy Ghost. This is the record of the Father, and of the Son, from henceforth and forever." (Chapter 6:64-66)
Baptism being a known ordinance among the Jews, the prophet could properly refer to it as the "waters of Judah."
Swear by the name of the Lord. Just how the custom of swearing by the divine Name originated is not known. It was common at the time of Moses, and became part of his law as a useful ceremony in the interest of peace and justice. In Mormon 5:1) Evil and secret oaths are noted and condemned.
Our Lord, as is well known, condemns swearing in the daily intercourse between man and man. Whatever is beyond the mere affirmation, or negation, "cometh of evil." (James 5:12). Yet, our Lord, when, during the legal proceedings against him, he was challenged under oath to say whether he was the Christ, the Son of God, he unhesitatingly replied in the affirmative; that is, as we should say, He testified under oath, not only that he was the Christ, the Son of God, but also that:
"Hereafter shall ye see the Son of man sitting on the right hand of power, and in the clouds of heaven." (64)