John Gill Bible Commentary

When thou liest down thou shalt not be afraid,.... That is, when thou liest down on thy bed at night in order to take sleep, having committed thyself into the hands of a faithful Creator and covenant God and Father, and of Christ the Redeemer and Wisdom of God; thou shalt not be afraid of thieves breaking in to hurt thy person or rob thee of thy property, or of fire to consume thy dwelling and substance, and of nocturnal apparitions and diabolical spectres deceiving thy sight and disturbing thy mind: or when thou art "asleep" (e), for so the word also signifies; thou shall not be surprised out of it with any of the above things, or terrified in it with uneasy imaginations, anxious cares, and distressing dreams; yea, thou shalt lie down, and thy sleep shall be sweet; free of all uneasy thoughts and cares, sound and refreshing, pleasant and comfortable, like that of the labouring man, Ecc 5:12; see Psa 4:8. This epithet of "sweet" is often given to "sleep" in poetic writings (f). (e) "dormieris", V. L. "eum dormies", Vatablus. (f) , Homer. Odyss. 7. v. 289. & 19. v. 511. Theocrit. Idyll. 11. v. 22, 23.