"Enough!".
Geb for one second there thought he was die by the hands of Shai, worthless god of fate who stole his consort's powers and is now proving to be stronger than him. He became really scared at some point within their fight, but he would rather die than show him the fear in his eyes. However, Isis' yell changed everything totally. When her sharp ear drum piercing scream came, he felt this great relief within him. For he was very sure there was no way he was going to ignore the fact that Isis was now conscious and was thinking straight. Of course she was his priority, Geb knew so because he was not oblivious of the way he was obsessed with her.
And like he predicted, Shai dropped him to the floor immediately. Not thinking twice at all and he moved his attention as well from him to Isis, the only one he loved.