1
general::
Complete something and either set it aside or send it on to the next step, as in We put the magazine to bed at ten, or They said they'd put the whole project to bed at least a month ago. This expression, transferring nighttime retirement to other kinds of completion, was first applied to a newspaper, where it meant "send to press," that is, start to print. [Mid-1900s]
American Heritage Idioms
2
general::
Phrase(s): put someone to bed [and] send someone to bed
to make someone go to bed. • Mother put Jimmy to bed and kissed him. • Sally was naughty and was sent to bed., Phrase(s): put something to bed
Fig. to complete work on something and send it on to the next step in production, especially in publishing. (From put someone to bed.) • This week’s edition is finished. Let’s put it to bed. • Finish the editing of this book and put it to bed.
McGrawhill's American Idioms And Phrasal Verbs