“see the pit.” The word translated “pit” is shachath (#07845 שַׁחַת), and it means “pit,” which was used for the grave; being dead (cp. Job 17:14; 33:18; Ps. 30:9; 103:4; Isa. 51:14; Ezek. 28:8). The translation “corruption” is in some versions because the same Hebrew root word means “ruin.”
Allen Ross writes: “But if the noun is from the verb ‘to ruin,’ a meaning ‘destruction’ would be more likely, as in Job 33:18, 22, 30. The Greek text translated the word with diphthoran, which means ‘destruction’ The idea of the line is being abandoned to the grave where the body would be gradually destroyed, but the word in the text seems to be related to ‘to sink down,’ and not ‘to destroy.’” (Kregel Exegetical Library: A Commentary on The Psalms).
Although we can see with 20-20 hindsight that this verse could be applied to the Messiah, there is no ancient evidence that it was until the death and resurrection of Christ. For one thing, nothing in the context points to the Messiah, it is a psalm of David. There is no mention of the Messiah in the psalm. Furthermore, we can tell that the people at the time of Christ did not apply this psalm to the Messiah because they did not think he was going to die (cp. Matt. 16:21-22; Luke 18:31-34; 24:19-21, 44-46; John 12:34; 20:9). There are many Scriptures in the Old Testament that speak of the Christ coming, killing the wicked, and setting up his kingdom on earth as if they were going to happen at the same time, and that is what the vast majority of Jews at the time of Christ believed (cp. Isa. 9:6-7; 11:1-9; 61:1-3; Micah 5:2; Zech. 9:9-10; Mal. 3:1-3; 4:1-3).