1.

LORD, who shall abide in thy tabernacle? who shall dwell in thy holy hill?

LORD. Hebrew. Jehovah. App-4 .
tabernacle = tent: i.e. dwelling, or home. Some codices, with one early printed edition, read "tents"; plural of majesty = Thy heavenly home. See App-40 .
dwell = abide continually. Figure of speech Anabasis . App-6 .
holy hill = holy mountain: i.e. Mount Zion; the type of the heavenly kingdom.

2.

He that walketh uprightly, and worketh righteousness, and speaketh the truth in his heart.

walketh = walketh habitually.
walketh . . . worketh . . . speaketh. Note Figure of speech Anabasis .
uprightly = without blame.
truth. First occurrence in the Psalms.

3.

He that backbiteth not with his tongue, nor doeth evil to his neighbour, nor taketh up a reproach against his neighbour.

He that = that never hath. So in the following two lines.
evil. Hebrew. ra'a'. App-44 .
neighbour = friend.
taketh up = receiveth.

4.

In whose eyes a vile person is contemned; but he honoureth them that fear the LORD. He that sweareth to his own hurt, and changeth not.

to his own hurt. Septuagint, Syriac, and Vulgate, read "to his neighbour".

5.

He that putteth not out his money to usury, nor taketh reward against the innocent. He that doeth these things shall never be moved.

usury. Compare Exodus 22:25 .Leviticus 25:36 , Leviticus 25:37 . Deuteronomy 23:19 , Deuteronomy 23:20 .
reward = bribery. Compare Exodus 23:8 . Deuteronomy 27:25 .
never be moved. See Psalms 15:1 . Contrast Psalms 9:15 , Psalms 9:17 , and compare Matthew 7:24-27 . Matthew 16:8 ; Mat 125:1 .