Charles Ellicott Commentary 1 Chronicles 9:31

"And Mattithiah, one of the Levites, who was the first-born of Shallum the Korahite, had the office of trust over the things that were baked in pans." — 1 Chronicles 9:31 (ASV)

The narrative returns to the functions of the Levites: And Mattithiah, one of the Levites (he was the firstborn of Shallum the Korahite), was (or is) in fixed charge over the making of the pancakes.

Mattithiah... firstborn of Shallum the Korahite. — The son of Shallum, or Meshelemiah, is called Zechariah (1 Chronicles 26:2). If Zechariah was the head of the main branch of Shallum’s family in David’s day, Mattithiah may have held that status in the time of the Chronicler or of the Chronicler’s source for this account.

Had the set office. — In other words, the duty of baking the sacred cakes for the grain offerings was hereditary in this branch of Shallum’s family.

Things that were made in the pans — i.e., "pancakes." The Hebrew term (hăbittim) occurs only here, but its meaning is established by the related word "baking-pan" (Ezekiel 4:3; mahăbath).