nau hia1勿心interjectionno need to care about it

於汝之心道使噫。勿心!

ie mua2 a hia1 po1 sui1 a. nau hia1!

Please use as you wish, don't be polite. / 请随便用,别客气!

勿心。

nau hia1.

Nevermind (literally "no relation") / 没关系。