beg to be excused

My proper course would have been to beg to be excused, then I should have had no more trouble in the matter; but it was not to be.

"But, sir—— " "I understand, but let me tell you that I have no fears, and I shall consequently beg to be excused from paying anything."

You can get whomsoever you please to take you to the fountain, but as for me I must beg to be excused.

As things were, he must beg to be excused.

But were he to become insistent and ask me to look into the matter for myself, I should beg to be excused.