Why do you think King James translators interpreted Isaiah Chapter 48

[Archaea]

verse one in this fashion:

1 Hear ye this, O house of Jacob, which are called by the name of Israel, and are come forth out of the awaters of Judah, which bswear by the name of the Lord, and make cmention of the God of Israel, but not in truth, nor in righteousness.

But 1 Nephi 20:1 states,

1 aHearken and hear this, O house of Jacob, who are called by the name of Israel, and are come forth out of the waters of Judah, or out of the waters of bbaptism, who cswear by the name of the Lord, and make mention of the God of Israel, yet they swear dnot in truth nor in righteousness.

the NRSV verse states:

Hear this, O house of Jacob,
who are called by the name of Israel,
and who came forth from the loins* of Judah;
who swear by the name of the Lord,
and invoke the God of Israel,
but not in truth or right.

The Masoretic Text states:

שִׁמְעוְּ־זֹאת בֵּית־יַעֲקֹב הַנִּקְרָאִים בְּשֵׁם יִשְׂרָאֵל וְּמִמֵּי יְהוְּדָה יָצָאוְּ הַנִּשְׁבָּעִים בְּשֵׁם יְהוָה וְּבֵאלֹהֵי יִשְׂרָאֵל יַזְכִּירוְּ לֹא בֶאֱמֶת וְלֹא בִצְדָקָה וְעַל־אֱלֹהֵי יִשְׂרָאֵל

The Masoretic Text doesn't refer to baptism but the waters of Jordan.