John Gill Commentary Psalms 28:8

"Jehovah is their strength, And he is a stronghold of salvation to his anointed." — Psalms 28:8 (ASV)

The Lord [is] their strength
The strength of his people, mentioned in (Psalms 28:9); not only the strength of David in particular, but of all his people in general; see (Psalms 37:39).

and he [is] the saving strength of his anointed;
meaning either himself, as before, who was anointed by Samuel king of Israel, and therefore had not invaded and thrust himself into an office he had no call and right unto; or the Messiah, the Lord's Anointed, whom he heard, helped, and strengthened in the day of salvation, and delivered him from the power of death and the grave, and raised him from thence, and gave him glory; see (Psalms 20:6).