I like the comment above about telling him it's important to make sure the agreement sticks that you have had outside counsel.

Also present your response to him as if you are in just as big a hurry to get it done as him.

"H, I'm really interested in getting this done. I want to make sure that there are no errors so that we don't get stuck with any confusion or mistakes. I will be seeing an attorney to review this on (Friday, tomorrow, this afternoon). Rest assured I want to move this process along expeditiously and am not trying to drag anything out."