Ezra 2:41

The singers: the children of Asaph, an hundred twenty and eight.

The verse belongs to the list in Ezra 1 and 2, specifically Ezra 2:1-65, of those who responded to Cyrus's decree or proclamation and went up and returned to Jerusalem. That list records those already returned with Zerubbabel in the first year of Cyrus, numbering 42,360 persons and described as nearly fifty thousand, after their captivity was ended by being made free to return. Those already returned are distinct from the Jews who still remained in Babylon and were invited to return. Within that return, the verse identifies the singers as the 128 children or descendants of Asaph among the returnees, which is stated without further explanation.