Māma zhǐ zhe wǒ de fángjiān shuō: "Kuài qù shōushi!"
Mom pointed at my room and said, "Go clean up now!"
Tips
grammar
着 (zhe) after a verb indicates a continuous or ongoing state. 指着 describes the action of pointing while doing something else, often followed by another verb: 指着...说.
culture
In Chinese culture, pointing directly at someone with your finger is considered rude. When indicating a person, it's more polite to gesture with an open hand.