expression
Archaic conditional particle used in kanbun-style Japanese, attaching to the auxiliary ず (negative) or the ~く form of adjectives. Equivalent to modern ~なければ or ~なくては. Rare outside classical or highly formal contexts.
See also: ずんば
「学ばずんば即ち已む」という言い回しがある。
There is a phrase 'If you do not learn, then stop' (using ずんば).
古い漢文訓読では「~くんば」の形で条件を表す。
In old kanbun reading, the form ~くんば expresses a condition.