Who shall ascend into the hill of the Lord? - Mount Zion; called the hill of the Lord, because it was the place designated for His worship, or the place of His abode. See the notes at Psalms 15:1. The idea here is, “Who shall ascend there with a view of abiding there? Who is worthy to dwell there?” The question is equivalent to asking, What constitutes true religion? What is required for the acceptable worship of God? What will prepare a person for heaven?
Or who shall stand in his holy place? - In the tabernacle, or in the place where he is worshipped. Compare the notes at Psalms 1:5. Who is worthy to stand before God? Who has the qualifications requisite to constitute the evidence of his friendship?