Ezra 2:42

• The singers played instruments and sang for worship at the temple (1 Chronicles 25:1–31; Psalms 73–83). The gatekeepers managed the temple gates and storehouses (1 Chronicles 9:26–27; 2 Chronicles 23:19; Nehemiah 12:25).

• Asaph was one of the three Levites King David appointed to lead music at the temple (1 Chronicles 16:5, 7). He wrote a collection of psalms (Psalms 50, 73–83). His family continued his work (1 Chronicles 25:1–7).

the priests...The Levites: Only seventy-four Levites returned to Jerusalem, which was a very low number. Ezra later worked hard to bring thirty-eight more with him (see study note on Ezra 8:18).

This chapter is Ezra's first major digression from the main story. The returning exiles needed to identify true Jews to maintain their community identity and theological purity. This helped them know whom they could marry and who could worship at the temple. This list is not the initial list of all Jews who returned to Jerusalem (compare Nehemiah 7:6–73). Instead, it is a slightly later list, created after Sheshbazzar died, of people who had settled in their towns.