ask (something) of
To request something of another person. I hope she doesn't ask that of me—I'm afraid I won't be able to say no. I'm sorry, but I'm not sure. Ask those questions of the boss.
ask something of someone or something
to request or demand something from someone, something, or a group. I want to ask something of you. We will ask that of the board of directors. You should ask that of your database.