In Ps. 116:19, the psalmist wants to go to the temple in Jerusalem. He will go the courts of the house of the LORD. There, he will bring sacrifices.
He will lift up the cup of salvation (v. 12). The cup of salvation is parallel to the sacrifice of thanksgiving in v. 17. He wrote in v. 17, “I will offer to you the sacrifice of thanksgiving” (Ps. 116:17). The cup of salvation points to the sacrifice of thanksgiving.
Thus, this cup is the drink offering associated with the thanksgiving meal (Lev. 7:11-21). It was a drink offering that was drunk after a meal that concluded with a thank offering. The drink offering with the thank offering, expressed “thanksgiving for the blessings of salvation.”
How then will the psalmist repay the LORD? He will lift up the cup of salvation. He will celebrate his salvation from death. He gives the reason in vv. 8-9, “For you have delivered my soul from death, my eyes from tears, my feet from stumbling; I will walk before the Lord in the land of the living” (Ps. 116:8-9).
 Robert G. Bratcher and William David Reyburn, A Translator’s Handbook on the Book of Psalms (New York: United Bible Societies, 1991), 982.