Psalms 50:14 - Joseph Benson’s Commentary on the Old and New Testaments

Offer unto God thanksgiving 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 a heart deeply affected with God's mercies, and is accompanied with such a course of life as is well pleasing to God. And pay thy vows unto the Most High Not ceremonial, but moral vows seem to be evidently meant here: the things required in this Psalm being opposed to sacrifices, and all ceremonial observances and offerings, and preferred before them. He means those substantial vows, promises, and covenants, which were the very soul of their sacrifices, and to which their sacrifices were but appurtenances and seals; namely, the vows whereby they did avouch Jehovah to be their God, and engaged to walk in his ways, Deuteronomy 26:17; and to love, serve, and obey him according to that solemn covenant which they entered into at Sinai, Exodus 24:3-8, and which they often renewed, and indeed did implicitly repeat in all their sacrifices, which were appointed for this very end, to confirm this covenant.