en_tn/act/23/12.md

Connecting Statement:

While Paul was in the prison at the fortress, the disbelieving religious Jews vow to kill him.

formed a conspiracy

"organized a group with a shared purpose" here, to kill Paul.

called a curse down upon themselves with an oath

The noun "curse" can be translated as a verb. It can also be made explicit what would cause them to be cursed. Alternate translation: "asked God to curse them if they did not do what they promised" (See: rc://en/ta/man/translate/figs-abstractnouns and rc://en/ta/man/translate/figs-explicit)