No rest for the weary
You must keep persevering no matter how tired or overworked you are.
A variant is “no rest for the wicked,” which implies that the devil will not allow his followers to rest from their evil doings.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.