Since Psalm 90:0 carries the caption: ‘a prayer of Moses’ and is clearly applicable to the exodus generation who all ‘return[ed] to … dust’ without entering the land of promise, Psalm 91:0 could well be labelled ‘a psalm for Joshua’, as some of its phrases fit this possibility quite naturally:
 ‘You will not fear the arrow that flies by day’ (Psalm 91:5), for instance, fired at you from the walls of Jericho or in any subsequent battles during the years of conquest;
 ‘no evil shall be allowed to … come near your tent’ (Psalm 91:10b, the temporary accommodation suitable not only for desert travel but for battlefield camping);
 ‘a thousand may fall at your side … You will … see the recompense of the wicked’ (Psalm 91:7-8, since ‘the iniquity of the Amorites’ was now complete … in the fourth generation’ since God promised their land to Abram, Genesis 15:16).
The psalm consists of two echoing halves (Psalm 91:1–8, 9–16). Each is introduced with the believer camping in the presence of ‘the Most High’ God (2, 9), the God worshipped and obeyed by Abram, the God of Melchisedek the priest (see Genesis 15:18, 19, 20, 22) – also acknowledged here as ‘the Lord’ (= YHWH, Psalm 91:2, 9) and ‘the Almighty’ (= Shaddai, another of Abram’s names for God, Genesis 17:1).
 Verses Psalm 91:3–8 give reasons for trusting this one true God: ‘For’ (Psalm 91:3): he will deliver from dreaded dangers and deadly weapons (Psalm 91:3); and he shields from fear (Psalm 91:5).
 In the second half of the psalm each stanza (Psalm 91:9– 3, 14– 6) is launched with another ‘because’. Now we are told how God will deliver and shield – the results of trusting him.
 Verses Psalm 91:9–13, ‘He will command his angels concerning you to guard you in all your ways. On their hands they will bear you up, lest you strike your foot against a stone.’ That’s what these unseen spiritual beings do; but there is also something we must do to cooperate: ‘You will tread on the lion and the adder’ (Psalm 91:13 a, b = Satan’s two main approaches in tempting the saints). Jesus showed us how to resist when Satan quoted only selected phrases from this psalm to try to snare him: but the devil had omitted the words ‘in all your ways’ and jumping presumptuously from a turret of the temple is certainly not one of Messiah’s ways! And he cleverly omitted verse 13 here. When Jesus resisted, then, indeed, ‘angels strengthened him’ (Matthew 4:11) thus fulfilling this word!
 Verses Psalm 91:14–16, the believer does more than shelter in the Lord, he also ‘holds fast to me in love’ (Psalm 91:14); therefore the Lord delivers him out of trouble and protects him in trouble, and exalts him beyond trouble; he also honours him; how? ‘With long life I will satisfy him’ – indeed with eternal life! ‘and show him my salvation’ (Psalm 91:16) including quality of life.