YOU SAID:

Heat not a furnace for your foe so hot that it do singe yourself.

INTO JAPANESE

敵が自分自身を焦がすほど熱く炉を加熱しないでください。

BACK INTO ENGLISH

Don't heat the furnace so hot that your enemies will scorch themselves.

INTO JAPANESE

敵が焦げるほど炉を熱くしないでください。

BACK INTO ENGLISH

Don't let the furnace get hot enough to scorch your enemies.

INTO JAPANESE

敵を焦がすほど炉が熱くならないようにしてください。

BACK INTO ENGLISH

Don't let the furnace get hot enough to scorch your enemies.