In this passage, the 1840 edition changed the last occurrence of prison to the plural prisons. This secondary reading continued in the RLDS textual tradition until the 1908 RLDS edition. This change to the plural was undoubtedly unintended since the preceding three occurrences of prison in this passage were left in the singular. For all other instances of the singular prison, the text has maintained the original number. However, there are two cases in the history of the text where an original plural prisons has been accidentally changed to the singular, in Alma 36:27 and in Alma 46:23; see under each of those passages for discussion.
Summary: Maintain in Ether 10:7 the singular prison in “to be wrought in prison”, the reading of the earliest extant text; the singular is used throughout the larger passage.