Charles Ellicott Commentary Ezra 3:4

"And they kept the feast of tabernacles, as it is written, and [offered] the daily burnt-offerings by number, according to the ordinance, as the duty of every day required;" — Ezra 3:4 (ASV)

According to the custom —It is necessary here to read Deuteronomy 16, Leviticus 23, and Numbers 29. The intention obviously is to lay stress on the provision made for an entire renewal of the Mosaic economy of service, as appears in the next verse.