Charles Spurgeon Commentary Isaiah 58:13-14

"If thou turn away thy foot from the sabbath, from doing thy pleasure on my holy day; and call the sabbath a delight, [and] the holy of Jehovah honorable; and shalt honor it, not doing thine own ways, nor finding thine own pleasure, nor speaking [thine own] words: then shalt thou delight thyself in Jehovah; and I will make thee to ride upon the high places of the earth; and I will feed thee with the heritage of Jacob thy father: for the mouth of Jehovah hath spoken it." — Isaiah 58:13-14 (ASV)

If thou turn away thy foot from the sabbath, from doing thy pleasure on my holy day; and call the sabbath a delight, the holy of the LORD, honourable; and shalt honour him, not doing thine own ways, nor finding thine own pleasure, nor speaking thine own words: then shalt thou delight thyself in the LORD;

There is no doubt that a reverent, happy, joyful keeping of the Sabbath greatly contributes to spiritual advancement. Here is the promise made to those who delight in the Sabbath.