Charles H. Spurgeon on Psalms 105:39

He spread a cloud for a covering. Never people were so favoured. What would not travellers in the desert now give for such a canopy? The sun could not scorch them with its burning ray; their whole camp was screened like a king in his pavilion. Nothing seemed to be too good for God to give his chosen nation, their comfort was studied in every way. And fire to give light in the night. While cities were swathed in darkness, their town of tents enjoyed a light which modern art with all its appliances cannot equal. God himself was their sun and shield, their glory and their defence. Could they be unbelieving while so graciously shaded, or rebellious while they walked at midnight in such a light? Alas, the tale of their sin is as extraordinary as this story of His love; but this Psalm selects the happier theme and dwells only upon covenant love and faithfulness. O give thanks unto the Lord for he is good. We, too, have found the Lord all this to us, for he has been our sun and shield, and has preserved us alike from the perils of joys and the evils of grief;

"He hath been my joy in woe,

Cheered my heart when it was low;

And with warnings softly sad

Calmed my heart when it was glad."

So has the promise been fulfilled to us, "the sun shall not hurt thee by day, nor the moon by night."