"and in your lying down": I might think, even if he retired in the middle of the day; "and in your rising": I might think, even if he rose in the middle of the day. It is, therefore, written "in your sitting in your house and in your walking upon the way." Scripture speaks of the common instance (i.e., the time when people normally retire and rise). Variantly: This is the dispute between Beth Hillel and Beth Shammai.
Beth Shammai say: In the evening all men recline and recite (the Shema), and in the morning they stand, it being written (lit.,) "and when you lie down and when you stand," and Beth Hillel say: All men recite in their (own) way, it being written "and when you walk upon the way." If so, what is the intent of "and when you lie down and when you rise"? The time when men (normally) retire, and the time when they (normally) rise.