This Psalm of Asaph begins with a principle sometimes neglected among those who would speak wisdom to others: you must first gain the attention of your listeners if you would teach them and reach them. v1 points us to listen for the purpose of learning. Most people most of the time listen for the purpose of replying, but here the Psalmist is asking us to listen to learn. This kind of listener is a disciple that submits to the words of his master, with reverence of mind, silent and earnest, that whatever is pronounced for the purpose of instruction may be heard and properly understood, and nothing be allowed to escape. He is a hearer of a different type, who hears with care, for the purpose of learning or imitation, not to criticize, or for animosity, or to argue, but rather for a time to expand his reality.
”I will open my mouth in a parable means he is making reference to a proverb or a parable and the dark sayings have in mind hidden knowledge, things that can simply be difficult to understand – riddles that are good topics for instruction. “The word for parable (masal) gives the book of Proverbs its title. Basically this means a comparison, like a saying which uses one realm of life to illuminate another.
Psalm 78:2 is a prophecy of the way Jesus would teach. See Matthew 13:35.
Centuries later the Apostle Paul would explain that one of the great advantages God gave to Israel was that He committed to them His word, the oracles of God, Romans 3:2. John records in his Gospel that in trying to persuade Jesus to keep providing miraculous bread, those who had been fed quoted this line from Psalm 78:24 “Our fathers ate the manna in the desert; as it is written, “He gave them bread from heaven to eat,” John 6:31. In quoting this psalm to Jesus, they fulfilled it in a negative way, showing the same ingratitude and willingness to test God that Israel showed in the wilderness with Moses. The “bread of heaven” did not rise from the earth, but descended from the clouds and so the words of the verse are literally accurate. Asaph had in mind the great power God showed in setting Israel free from their 400 years of slavery in Egypt. The exodus redemption is often presented in the Hebrew Scriptures as a demonstration of the power of God. “They did not remember his power, the day when He redeemed them from the enemy” Psa. 78:42. In the New Testament we have a new and ultimate demonstration of the power of God: the resurrection of Jesus Christ (Rom. 1:4, Eph. 1:19-20 & Php. 3:10). Paul might have rephrased Psa. 78:42. They did not remember His power, the day when He raised Jesus from the dead. This we should do every single time we praise Him who loves us!