John Wesley on Psalms 50:14

Offer - If thou wouldest know what sacrifices I prize, and indispensably require, in the first place, it is that of thankfulness, proportionable to my great and numberless favours; which doth not consist barely in verbal acknowledgments, but proceeds from an heart deeply affected with God's mercies, and is accompanied with such a course of life, as is well - pleasing to God. Vows - Those substantial vows and promises, which were the very soul of their sacrifices.