There is this famous quote reputedly from 山本五十六:
やってみせて、言って聞かせて、やらせてみて、 ほめてやらねば人は動かじ。(source)
やってみせ、言ってきかせて、させてみて、誉めてやらねば人は動かじ。(a different version. source)
Do it and show'em; say things and make'em listen; try and let'em do things; and if you don't praise people (for what they do), people don't lift a finger. (My rendering)
It appears 動かじ = 動かず, but I can't find anything on Wikipedia's 四つ仮名 page about this conversion. Is this a marker of Early Modern Japanese or a dialect?
