Meaning of 金棒 in Japanese

Definition of 金棒

かなぼう(kanabou) 【金棒】

(n) metal rod
君が英語ができれば鬼に金棒なんだが。
If you could only speak English, you would be perfect.

かなぼうひき(kanabouhiki) 【金棒引き ·鉄棒引き】

おににかなぼう(oninikanabou) 【鬼に金棒】

(exp) making a strong person even stronger (like giving a metal rod to an ogre); as strong as can be

君きみが英語えいごができれば鬼に金棒かなぼうなんだが。

If you could only speak English, you would be perfect.

君きみがここにいているくれるなら、なにも怖いこわいものなし。鬼に金棒かなぼうだよ。

With you here beside me I'm not afraid of anything. You're my fortress.