A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
psa 15:1Those who are fit for communion with God may be known by a conformity to His law, which is illustrated in various important particulars. (Psa 15:1-5)
abide--or, "sojourn" (compare Psa 5:4), where it means under God's protection here, as (Psa 23:6, Psa 27:4, Psa 27:6) communion.
tabernacle--seat of the ark (Sa2 6:17), the symbol of God's presence.
holy hill--(Compare Psa 2:6).
psa 15:2walketh--(Compare Psa 1:1).
uprightly--in a complete manner, as to all parts of conduct (Gen 17:1), not as to degree.
righteousness--what is right.
in his heart--sincerely (Pro 23:7).
psa 15:3He neither slanders nor spreads slander.
psa 15:4Love and hate are regulated by a regard to God.
sweareth . . . hurt--or what so results (compare Lev 5:4).
psa 15:5(Compare Lev 25:37; Deu 23:19-20).
usury is derived from a verb meaning "to bite." All gains made by the wrongful loss of others are forbidden.
taketh reward, &c.--The innocent would not otherwise be condemned (compare Exo 23:8; Deu 16:19). Bribery of all sorts is denounced.
doeth these, &c.--Such persons admitted to God's presence and favor shall never be moved (Psa 10:6; Psa 13:5).