Esther 5:8, 14

if I have found favour in the sight of the king, and if it please the king to grant my petition, and to perform my request, let the king and Haman come to the banquet that I shall prepare for them, and I will do to morrow as the king hath said.

Then said Zeresh his wife and all his friends unto him, Let a gallows be made of fifty cubits high, and to morrow speak thou unto the king that Mordecai may be hanged thereon: then go thou in merrily with the king unto the banquet. And the thing pleased Haman; and he caused the gallows to be made.