Here the words “them” and “they” refer to the apostles.
They did not go into the temple building where only the priests were allowed. AT: “in the temple courtyard … into the temple courtyard” (See: rc://en/ta/man/translate/figs-explicit)
This is a reference to the gospel message that the apostles had already proclaimed. Possible meanings are 1) “all this message of eternal life” or 2) “the whole message of this new way of living” (See: rc://en/ta/man/translate/figs-metonymy)
“as it began to be light.” Although the angel led them out of the jail during the night, the sun was rising by the time the apostles reached the temple courtyard.
This implies someone went to the jail. AT: “sent someone to the jail to bring the apostles” (See: rc://en/ta/man/translate/figs-ellipsis)