Hit the hay
"Hit the hay" is an informal idiom that means to go to bed or to go to sleep. The phrase originates from the practice of farmers and ranchers in the past who would hit or beat hay with a pitchfork to fluff it up before bedding down for the night. Over time, the expression evolved to simply mean going to sleep. It is often used casually and colloquially to indicate the intention to retire for the night or take a nap. For example, someone might say, "I'm exhausted; I'm going to hit the hay early tonight."
This idiom is widely understood and used in everyday conversation to convey a relaxed or informal tone when referring to bedtime. It reflects the universal need for rest and relaxation after a long day's work or activities. Whether used humorously or matter-of-factly, "hit the hay" remains a common way to express the simple act of going to bed.