The number 642 appears as a census figure in the Bible, but it has no well-established symbolic meaning in biblical or Jewish tradition.
The number 642 appears in the large population registers kept after the exile in Babylon. In Ezra 2:10, the number of descendants of Bani is given as 642, and in Nehemiah 7:62 the same number is used for the descendants of Delaiah, Tobijah, and Nekoda—groups that could not document their Israelite origin. These lists serve an important theological function by emphasizing continuity between pre-exilic Israel and the restored community. Although 642 does not carry an independent symbolic meaning like numbers such as 7 (perfection), 12 (the tribes of Israel), or 40 (testing), its occurrence testifies to the precise record-keeping that characterizes the post-exilic period. In Nehemiah 7:62, the 642 individuals are associated with families who could not prove their lineage with Israel, raising the question of who belonged to the restored covenant people. The population registers in Ezra 2 and Nehemiah 7 are regarded by historians as important sources for understanding the demographic and social rebuilding of Judah after the Babylonian exile (around 538 BC). Through gematria, the number 642 can be analyzed by searching for Hebrew words or phrases with a corresponding numerical value, but there is no established tradition that assigns this number any special kabbalistic or rabbinic meaning.*