Martin Luther on Psalms 121:6

Verse. 6. The sunne shall not hurt thee by day, nor the moone by night.

The heate of the Sunne maketh mens bodyes weake & feeble. So doth the Moone also hurt, not onely with colde, but also with moysture. By these speeches he meaneth all maner of tentations and perils, and that God will be with vs in the middest of them, to succour vs and to deliuer vs, albeit we seeme for a litle while to beare all the heate and burden of the day alone: that is, to be vtterly forsaken and destitute of all helpe and succour. But if we were alone, then should the tentation haue no ende, yea it should presently swallow vs vp: for we are not able of our selues to endure the space of one moment. Now the Lord suffreth Satan to vomet out his poyson and to practise against vs the beginning of his malice: but he will not suffer him to hurt so much as he would doe. Therefore because we haue the shadowe to couer vs, euen the presence & mightie protection of the Lord, we should patiently endure the beginning of sorrowes, that is to say, the light, short, and momentane afflictions of this life, beeing sure that euen in death our life is hidden and safely kept with Christ in God, and we shall ouercome all the fiery darts and cruel assaults of Satan.