Psalms 81:3

All the worship we can render to the Lord is beneath his excellences, and our obligations to him, especially in our redemption from sin and wrath. What God had done on Israel's behalf, was kept in remembrance by public solemnities. To make a deliverance appear more gracious, more glorious, it is good to observe all that makes the trouble we are delivered from appear more grievous. We ought never to forget the base and ruinous drudgery to which Satan, our oppressor, brought us. But when, in distress of conscience, we are led to cry for deliverance, the Lord answers our prayers, and sets us at liberty. Convictions of sin, and trials by affliction, prove his regard to his people. If the Jews, on their solemn feast-days, were thus to call to mind their redemption out of Egypt, much more ought we, on the Christian sabbath, to call to mind a more glorious redemption, wrought out for us by our Lord Jesus Christ, from worse bondage.

Blow up the trumpet in the new moon. Announce the sacred month, the beginning of months, when the Lord brought his people out of the house of bondage. Clear and shrill let the summons be which calls all Israel to adore the Redeeming Lord. In the time appointed, on our solemn feast day. Obedience is to direct our worship, not whim and sentiment: God's appointment gives a solemnity to rites and times which no ceremonial pomp or hierarchical ordinance could confer. The Jews not only observed the ordained month, but that part of the month which had been divinely set apart. The Lord's people in the olden time welcomed the times appointed for worship; let us feel the same exultation, and never speak of the Sabbath as though it could be other than "a delight" and "honourable." Those who plead this passage will keep such feasts as the Lord appoints, but not those which Rome or Canterbury may ordain.