Pharaoh is starting to change his mind a little – but not enough. He is willing (really?) for Moses to go – but only under conditions. This is really about control and power. Pharaoh can’t truly acknowledge that the Lord is in control, that the Lord has all the power. Pharaoh wants to hold on to the power – by adding in conditions.
I have found that I do this with God all the time. He calls me to be obedient, and I want to follow Him. I love Him and know His way is best. And yet I tell Him, “I will only do this if…” – I put conditions on my obedience. Sometimes that means I miss what God wants for my life; sometimes it means my life is worse because I am not willing to fully obey Him.
Pharaoh wants to limit God – but God will not be limited by our conditions. When God does not allow Himself to be limited, Pharaoh becomes stubborn and throws a fit – much like we do today.