Unless you’re an avid hacky sacker, telling someone you’re going to “hit the sack” means you’re going to bed. As far as idioms go, this one is widely understood in English. But its origins are less clear. In order to better understand this playful phrase, let’s look at a similar idiom: “hit the hay.”
According to the Oxford English Dictionary, “hit the hay” was likely coined sometime in the early 1900s — decades before “hit the sack” made an appearance. We can likely attribute this to the fact that some of the earliest beds were just piles of hay and grass, providing a bit of soft cushioning from the hard ground. When someone said “hit the hay,” they were likely referencing the rudimentary beds people slept on long before soft memory foam mattresses were created.
People also needed a way to contain loose hay. There’s evidence going all the way back to ancient Egypt that people were stuffing grasses, hay, and straw into bags for a mattress, and this practice was widespread across cultures for centuries. By 1825, the term “sack” became popular slang among sailors to refer to their bedding. If you were a sailor on “sack duty,” that meant you were sleeping. But the idiom “hit the sack” only gained wide recognition in the mid-20th century. An early printed example is found in the 1943 war diary of James J. Fahey, who served as a sailor on the Pacific front in World War II. He wrote: “I hit the sack at 8 p.m. I slept under the stars on a steel ammunition box two feet wide.”
So, if you say you’re going to “hit the sack” or “hit the hay,” it’s all a reference to how people slept in in the past. Fortunately for all of us, comfortable mattresses found at stores today are several steps above a hay-stuffed sack, even if you do have to fight with your dog for space.
