The heading consists of two parts: to the choirmaster and a Psalm of David. Choirmaster is the name or title of someone who oversees or directs the singing. Here it probably refers to someone directing the singing by means of playing an instrument. You could also say, for the master of music. The Hebrew word for psalm is derived from praising/singing. The word psalm comes from the Greek translation of it and points to the playing of a stringed instrument. Of David can sometimes also mean belonging to David’s legacy. One could think of this when the psalm clearly speaks about the temple (which, after all, was built after David had died). Here, that is not necessary, for the sanctuary of Psalm 20:2 can very well have been the place where the ark of the covenant stood.

Various commentators are of the opinion that the psalm was sung (as a prayer) before the king departed to do battle. A war or a battle in the field was tense, for your life was in danger; that is why it says, in the day of trouble. Looking at this beginning—Psalm 20:1b—it is quite possible that the psalm was sung before the army set out for war.

The phrase, may the Lord answer (react to) you, means that the Lord reacts by giving the victory. In the second part of verse 1b: May the name of the God of Jacob protect you, the name refers to God himself. The name of Jacob’s God reminds us of the miraculous way in which the Lord protected Jacob and his family, after they incurred the wrath of the environment (see Genesis 34:1–31). You also read about God’s protection in Genesis 35:5. Jacob has experienced God’s protection before. That is why in various places in the Bible, you can read about the help or protection of the God of Jacob, as, for example, in Psalm 146:5.