For it is a statute for Israel,
An ordinance of the God of Jacob.
The commands to sing for joy, raise a song, and blow the trumpet are neither shackles nor coercions, but keys that unlock the soul again and again from the relentless attacks of evil. Sin has no business worshiping God. Sin as a power in us holds captive those that do not worship God. But those that put to death the deeds of darkness delight in the light and worship the One who bestowed upon them such power that set them free. When those with such power act as slaves to sin, they need this call and they need this statute.
The following is taken directly from The Treasury of David by Spurgeon.
For this was a statute for Israel, and a law of the God of Jacob. It was a precept binding upon all the tribes that a sacred season should be set apart to commemorate the Lord’s mercy; and truly it was but the Lord’s due, he had a right and a claim to such special homage. When it can be proved that the observance of Christmas, Whitsuntide, and other Popish festivals was ever instituted by a divine statute, we also will attend to them, but not till then. It is as much our duty to reject the traditions of men, as to observe the ordinances of the Lord. We ask concerning every rite and rubric, “Is this a law of the God of Jacob?” and if it be not clearly so, it is of no authority with us, who walk in Christian liberty.
HINTS TO THE VILLAGE PREACHER
The rule of ordinances and worship; pleas for going beyond it; instances in various churches; the sin and danger of such will worship.