en_tn/2ki/11/12.md

brought out the king's son Joash

Jehoiada, the high priest, brought king Ahaziah's son, Joash, out from the temple apartment where he had been raised in hiding.

gave him the covenant decrees

"presented him with the book of the law"

anointed him

The priest poured olive oil on the head of Joash as a symbol that he was now the king. AT: "poured some olive oil on Joash's head" (See: rc://en/ta/man/translate/translate-symaction)

clapped their hands

Clapping their hands was a sign of the happiness of the people at the anointing of the new king.