Ian Paisley explains how the Psalms, for example, Psalm 40, are messianic and prophetic, revealing Christ and the heart of God. Ian teaches that the more one reads the Bible, the more is revealed, and the more one is amazed as the freshness and newness of that revelation. Psalm 40 preaches Christ. "Blessed is that man that maketh the Lord his trust, and respecteth not the proud, nor such as turn aside to lies. Many, O Lord my God, are thy wonderful works which thou hast done, and thy thoughts which are to us-ward: they cannot be reckoned up in order unto thee: if I would declare and speak of them, they are more than can be numbered. Sacrifice and offering thou didst not desire; mine ears hast thou opened: burnt offering and sin offering hast thou not required. Then said I, Lo, I come: in the volume of the book it is written of me; I delight to do thy will, O my God: yea, thy law is within my heart. I have preached righteousness in the great congregation: lo, I have not refrained my lips, O Lord, thou knowest. I have not hid thy righteousness within my heart; I have declared thy faithfulness and thy salvation: I have not concealed thy lovingkindness and thy truth from the great congregation. Withhold not thou thy tender mercies from me, O Lord: let thy lovingkindness and thy truth continually preserve me." (Psalm 40:4-11). Follow along in the Bible here: https://www.biblegateway.com/passage/?search=psalm+40&version=KJV.
The original audio for this sermon from 1983 is hosted here: http://www.sermonaudio.com/sermoninfo.asp?SID=4863/ Hundreds more Ian Paisley sermons and bible lessons are available for free on sermonaudio.com here: http://www.sermonaudio.com/search.asp?currpage=8&keyword=Dr%2E_Ian_R%2E_K%2E_Paisley&SpeakerOnly=true&currSection=sermonsspeaker&AudioOnly=false&sortby=oldest.
Or, see my playlist on YouTube which comprises an assorted collection of Ian Paisley sermons here: https://www.youtube.com/playlist?list=PLcn1lQpV3MPYULnQeo4wy_5veVGPGVaeU
.