Albert Barnes Commentary 2 Chronicles 24:16

"And they buried him in the city of David among the kings, because he had done good in Israel, and toward God and his house." — 2 Chronicles 24:16 (ASV)

They buried him in the city of David among the kings — This unparalleled honor, due in part to the respect felt for Jehoiada’s religious character, was probably also in part attributable to his connection with the royal family through his wife (2 Chronicles 22:11), and to the fact that for ten or twelve years, he had practically held the kingly office.

Toward his house — that is, toward God’s house, the temple.