I would explain it as a open handed cradle that the bow grip or handle lays in when at full draw. Your bow grip lays between your thumb and in te valley of your hand. What you're trying not to do is grip the bow and torch it by gripping it firmly.

Your bow arm at full draw is not tense or muscle flexed either nor relaxedwith aslightly bend at the elbow. Your bow arm is more a post that holds the bow out in front of you at full draw.

Hopefully that explains it. Just my .02