What does the Bible say about vows and promises to God?

In Scripture, vows are often seen in the context of God's promises. For instance, Jacob's vow in Genesis 28 was not merely a deal with God but an acknowledgment of God's faithfulness to him. It was based on the understanding that God had already promised certain things to Jacob. This highlights that our relationship with God is founded on His grace and promise rather than on our ability to make and keep vows. Therefore, when David mentions in Psalm 61 that God has heard his vows, it points to the assurance of God's commitment to His people, rather than a mercenary-like agreement where we strive to earn His favor.