oper-, opus
(Latin: work)
si opus sit; si op. sit.
If it be necessary.
Used sometimes when writing a medical prescription.
Venit nox, quando nemo potest operari.
The night comes when no man can work.
A translation from a Greek statement ["Night that puts to rest the works of men" by Apollonius Rhodius, Argonautica (c. 225 B.C.)] as translated in The Vulgate version of John, ix, 4. (c. A.D. 70) from the New Testament part of the Bible.
