Esther 2:10

2:10 Now Esther had not disclosed her people or her lineage, for Mordecai had instructed her not to do so.

Esther 6:2

6:2 it was found written that Mordecai had disclosed that Bigthana and Teresh, two of the king’s eunuchs who guarded the entrance, had plotted to assassinate King Ahasuerus.

Esther 3:4

3:4 And after they had spoken to him day after day without his paying any attention to them, they informed Haman to see whether this attitude on Mordecai’s part would be permitted. Furthermore, he had disclosed to them that he was a Jew.