Pedro, I am not sure to understand your question correctly, but I try to answer

Master remain master. Slave will not return your 4 bytes without a proper request. When you want the 4 bytes back to the master then you make the request with:
Code:
I2CRead SDA,SCL,I2Caddress,[str YourBuffer\4], bogus
and you will find the four bytes into the array YourBuffer that you have properly declared in your MASTER.

Al.