1 Psa 91:1-16. David is the most probable author; and the pestilence, mentioned in 2Sa 24:13-15, the most probable of any special occasion to which the Psalm may refer. The changes of person allowable in poetry are here frequently made.
dwelleth in the secret place - (Psa 27:5; Psa 31:20) denotes nearness to God. Such as do so abide or lodge secure from assaults, and can well use the terms of trust in Psa 91:2.

3 snares ... [and] ... noisome pestilence - literally, "plagues of mischiefs" (Psa 5:9; Psa 52:7), are expressive figures for various evils.

4 For the first figure compare Deu 32:11; Mat 23:37.
buckler - literally, "surrounding" - that is, a kind of shield covering all over.

5 terror - or, what causes it (Pro 20:2).
by night - then aggravated.
arrow - that is, of enemies.

7 The security is more valuable, as being special, and, therefore, evidently of God; and while ten thousands of the wicked fall, the righteous are in such safety that they only see the calamity.

9 This exemption from evil is the result of trust in God, who employs angels as ministering spirits (Heb 1:14).

13 Even the fiercest, strongest, and most insidious animals may be trampled on with impunity.

14 God Himself speaks (compare Psa 46:10; Psa 75:2, Psa 75:3). All the terms to express safety and peace indicate the most undoubting confidence (compare Psa 18:2; Psa 20:1; Psa 22:5).
set his love - that of the most ardent kind.

16 show him - literally, "make him see" (Psa 50:23; Luk 2:30).