Psalm 18:30 New English Translation

³⁰The one true God acts in a faithful manner;^[a]
the Lord’s promise^[b] is reliable.^[c]
He is a shield to all who take shelter^[d] in him.

Psalm 18:30 tn Heb “[As for] the God, his way is blameless.” The term הָאֵל (haʾel, “the God”) stands as a nominative (or genitive) absolute in apposition to the resumptive pronominal suffix on “way.” The prefixed article emphasizes his distinctiveness as the one true God (cf. Deut 33:26). God’s “way” in this context refers to his protective and salvific acts in fulfillment of his promise (see also Deut 32:4; Pss 67:2; 77:13 [note vv. 11-12, 14]; 103:7; 138:5; 145:17).
Psalm 18:30 sn The Lord’s promise. In the ancient Near East kings would typically seek and receive oracles from their god(s) prior to battle. For examples, see R. B. Chisholm, “An Exegetical and Theological Study of Psalm 18/2 Samuel 22” (Th.D. diss., Dallas Theological Seminary, 1983), 241-42.
Psalm 18:30 tn Heb “the word of the Lord is purified.” The Lord’s “word” probably refers here to his oracle(s) of victory delivered to the psalmist before the battle(s) described in the following context. See also Pss 12:5-7 and 138:2-3. David frequently received such oracles before going into battle (see 1 Sam 23:2, 4-5, 10-12; 30:8; 2 Sam 5:19). The Lord’s word of promise is absolutely reliable; it is compared to metal that has been refined in fire and cleansed of impurities. See Ps 12:6.
Psalm 18:30 sn Take shelter. See the note on the word “shelter” in v. 2.

New English Translation (NET)