וַיָּב֕וֹא עַ֖ד לִפְנֵ֣י שַֽׁעַר־הַמֶּ֑לֶךְ כִּ֣י אֵ֥ין לָב֛וֹא אֶל־שַׁ֥עַר הַמֶּ֖לֶךְ בִּלְב֥וּשׁ שָֽׂק׃
and he came even before the king’s gate; for none might enter within the king’s gate clothed with sackcloth.
Rashi on Esther
For one could not enter. It is improper to enter the king’s gate dressed in sackcloth.