It was probably his right side; that’s not certain, but from the description it was probably the right side, between the ribs. “The spear apparently went through the right lung and into the heart, so when the spear was pulled out, some fluid—the pericardial effusion and the pleural effusion—came out. This would have the appearance of a clear fluid, like water, followed by a large volume of blood, as the eyewitness John described in his gospel.”