Echad

The Theological Wordbook of the Old Testament has the following information on the word echad:

This word occurs 960 times [there exists a discrepancy on the number of occurrences between authors] as a noun, adjective, or adverb, as a cardinal or ordinal number, often used in a distributive sense. It is closely identified with yahad “to be united” and with ro’sh “first, head,” especially in connection with the “first day” of the month (Gen 8:13). It stresses unity while recognizing diversity within that Oneness. Sometimes the phrase ” as one man” can mean “all at once” (Num 14:15), but when Gideon was told he would defeat Midian ” as one man” it probably meant ” as easily as a single man” (Jud 6:16) The phrase can also refer to a nation aroused to take united action against gross injustice (Jud 20:8; I Sam 11:7). Zephaniah’s mention of people serving God “with one shoulder” (3:9) likely means “shoulder to shoulder,” solidly united. Likewise in Ex 24:3 “with one voice” expresses that all Israel was involved in entering into the Covenant with Yahweh. The concept of unity is related to the tabernacle, whose curtains are fastened together to form one unit (Ex 26:6, 11; 36:13). Adam and Eve are described as “one flesh” (Gen 2:24), which includes more than sexual unity. In Gen 34:16 the men of Shechem suggest intermarriage with Jacob’s children in order to become “one people.” Later, Ezekiel predicted that the fragmented nation of Israel would someday be reunited, as he symbolically joined two sticks (37:17). Once again Judah and Ephraim would be one nation with one king (37:22). Abraham was viewed as “the one” from whom all the people descended (Isa 51:2; Mal 2:15), the one father of the nation. Diversity within unity is also seen from the fact that `echad has a plural form, `ahadim. It is translated “a few days” in Gen 27:44; 29:20, and Dan 11:20. In Gen 11:1 the plural modifies “words”: “the whole earth used the same language and the same words.” Apparently it refers to the same vocabulary, the same set of words spoken by everyone at the tower of Babel. The first “same” in Gen 11:1 is singular , analogous to “the same laws” of the Passover applying to native-born and foreigner (Ex 12:49; cf. Num 15:16), or to the “one law” of sure death for approaching the Persian king without invitation (Est 4:11). In the famous Shema of Deut 6:4, “Hear, O Israel….the LORD is one,” the question of diversity within unity has theological implications. Some scholars have felt that, though “one” is singular, the usage of the word allows for the doctrine of the Trinity. While it is true that this doctrine is foreshadowed in the OT, the verse concentrates on the fact that there is but one God and that Israel owes it exclusive loyalty to him (Deut 5:9; 6:5)” (Harris, Archer, Waltke, Volume 1, p.30).