en_tn_condensed/act/16/04.md

General Information:

The word "they" here refers to Paul, Silas (Acts 15:40), and Timothy (Acts 16:3).

the decrees to obey

"the decrees for the church members to obey" or "teh decrees for the believers to obey"

that were decided on by the apostles and elders who were in Jerusalem

This can be stated in active form. Alternate translation: "that the apostles and elders in Jerusalem had decided on" (See: rc://en/ta/man/jit/figs-activepassive)