put to it, be
Be confronted with a severe difficulty, as in I was put to it to finish this book on time. This usage is derived from the active sense of put to it, that is, “force or challenge someone to something.” [c. 1600]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.