“And you shall speak of them when you sit at home, and when you walk along the way, and when you lie down and when you rise up.”
Literally: go / walk – reside – sit – lie down
Alternately: The four fundamental activities: moving about and staying in place, sitting and lying down (to sleep). By extension, everyday life; normal day-to-day activity. All the time, “day in, day out.”
Notes: The 坐 can also be written as 座, with exactly the same pronunciation and meaning.
This compound is apparently derived from a Buddhist chant known as the “Contemplation on the Mind-Ground” sutra (心地観経, shin.ji.kan.gyou). These four activities or states are also referred to as the 四威儀 or 四儀 (both pronounced shigi), the “four postures.”