tranquillity
2 occurrences across the corpus
King James Version
Daniel 4:27
Wherefore, O king, let my counsel be acceptable unto thee, and break off thy sins by righteousness, and thine iniquities by shewing mercy to the poor; if it may be a lengthening of thy tranquillity.
OT Pseudepigrapha
The Letter of Aristeas 9:66
The king graciously acknowledged the answer and asked the eleventh (since there were two more than seventy), how he could in time of war maintain tranquillity of soul?