This direction from the lips of Jehovah is for our instruction. The Bible is a perfect guide, and if its pages are prayerfully studied by hearts willing to understand, none need err upon this question. (6T 355.1) MC VC

Many need instruction as to how they should appear in the assembly for worship on the Sabbath. They are not to enter the presence of God in the common clothing worn during the week. All should have a special Sabbath suit, to be worn when attending service in God’s house. While we should not conform to worldly fashions, we are not to be indifferent in regard to our outward appearance. We are to be neat and trim, though without adornment. The children of God should be pure within and without. (6T 355.2) MC VC

On Friday let the preparation for the Sabbath be completed. See that all the clothing is in readiness and that all the cooking is done. Let the boots be blacked and the baths be taken. It is possible to do this. If you make it a rule you can do it. The Sabbath is not to be given to the repairing of garments, to the cooking of food, to pleasure seeking, or to any other worldly employment. Before the setting of the sun let all secular work be laid aside and all secular papers be put out of sight. Parents, explain your work and its purpose to your children, and let them share in your preparation to keep the Sabbath according to the commandment. (6T 355.3) MC VC