He should ask his mother why he is this way.

When it comes to those who deny his (Baha's) claims. It’s just that the House isn’t keen to translate those bits of his letters. One of many passages:

تالله الحق من ينكر هذا الفضل الظاهر الباهر المتعالي المنير ينبغي له بان يسئل من امه حاله فسوف يرجع الی اسفل الجحیم

By God, the Truth! One who denies this luminous, exalted, dazzling, evident grace should ask his mother why he is this way. He will return to the nethermost fire. (Ma’idih, 4:355)