I recently read a document posted by a user in QF, who said that "In the past, I have calibrated simple short rate models to the term structure by using maximum likelihood to get the parameters of the Vasicek/CIR sde and then use the ZCB formula and the current yield curve to calibrate the market price of risk."
I can not fully understand how having a knowledge of ZCB formula and yield curve leads to finding the market price of risk. For example, if we are working under a CIR model for the short rate, we need to know the ZCB price formula, which has the form of $A(t, T) e^{-B(t, T)r_t}$. Then, where can I use the data on the yield curve to calibrate the market price of risk? Should I say that the market price of risk is obtained by minimizing the difference between the ZCB model price and ZCB market price? I still do not know where I should use yield curve.