"Echad" (Heb "one") is a numerical adjective which appears 650
times in the OT, and at no time does this word itself carry the idea of
plurality. While it is true that "echad" is sometimes found modifying a
collective noun -- one family, one herd, one bunch, etc -- the sense of
plurality actually resides in the compound noun, and not in the word "echad"!
Echad appears in translation as the numeral "one", and also as "only", "alone",
"undivided", and "single." Its normal meaning is "one and not two", as we find
in Ecc 4:8. Abraham was "only one man" ("echad") in the NIV's rendition of Eze
33:24, and he was "alone" ("echad") in the KJV translation of Isa
Koehler and Baumgartner's Hebrew and Aramaic Lexicon of the
Old Testament (1967) clearly states that the fundamental definition of "echad"
is "one single."
The truth of this is reaffirmed by a Trinitarian professor of
theology who concedes that the popular Trinitarian argument from "echad" is even
more frail than the argument from "elohim" (ie based on Gen 1:26;
see Lesson, Gen 1:26, "Us"): "Even weaker is the
argument that the Hebrew word for 'one' ("echad") used in the Shema ('Hear O
Israel, the Lord our God is one Lord') refers to a united one, not an absolute
one. Hence, some Trinitarians have argued, the OT has a view of a united
Godhead. It is, of course, true that the meaning of the word may in some
contexts denote a unified plurality (eg, Gen 2:24, "they shall become one
flesh"). But this really proves nothing. An examination of the OT usage reveals
that the word "echad" is as capable of various meanings as is our English word
one. The context must determine whether a numerical or unified singularity is
intended" (G Boyd, "Oneness Pentecostals and the Trinity").