I will take the cup of salvation - Compare the notes at Psalms 11:6. The “cup of salvation” means the cup by which his sense of the greatness of the salvation might be expressed - the cup of thanksgiving. Compare the notes at 1 Corinthians 10:16. The reference seems to be to a custom in festivals of drinking a cup of wine as a special expression of thanks or of obligation. The act would be more solemn, and the truth more deeply impressed on the mind, when accompanied by some religious rite - some ceremonial, as in the Lord’s Supper, expressly designed to call the mercy of God to remembrance.
And call upon the name of the Lord - Engage in a solemn act of devotion; make it a matter of special ceremony or observance to call the mercy of God to remembrance. This was one way of rendering to the Lord a return for the benefits received at his hands; as it is now. Christians do this at the table of the Lord - in the observance of the Lord’s Supper.