After the three masters approached the Ten Directions Platform Market, they didn't necessarily intend to enter. They merely wanted to see if there was a master overseeing the market.
At this moment, Xia Nichang's powerful divine sense was needed—her divine sense exploration not only reached far but was also very detailed.
After probing, she indicated that there was indeed a Golden Core in the market, but it was only at the Initial Golden Core Stage. As for who it was specifically, she couldn't discern.
Firstly because she was worried about an ambush and getting discovered, and secondly, because the Ten Directions Platform's cultivation technique... wasn't very distinctive.