…unto thee shall the vow be performed. – Psalm 65:1

It has been the habit of godly men to make vows occasionally, in times of pain, and losses, and affliction…You said, “If I am ever raised up, and my life is prolonged, it shall be better spent.” You said, also, “If I am delivered out of this great trouble, I hope to consecrate my substance more to God.” Another time you said, “If the Lord will return to me the light of His countenance, and bring me out of this depressed state of mind, I will praise Him more than ever before.” Have you remembered all this? Coming here myself so lately from a sick bed, I at this time preach to myself. I only wish I had a better hearer; I would preach to myself in this respect, and say, “I charge thee, my heart, to perform thy vow.” Some of us, dear friends, have made vows in time of joy, the season of the birth of the first-born child, the recovery of the wife from sickness, the merciful restoration that we have ourselves received, times of increasing goods, or seasons when the splendor of God’s face has been unveiled before our wondering eye. Have we not made vows, like Jacob when he woke up from his wondrous dream, and took the stone which had been his pillow, and poured oil on its top, and made a vow unto the Most High? We have all had our Bethels. Let us remember that God has heard us and let us perform unto Him our vow which our soul made in her time of joy. But I will not try to open the secret pages of your private note-books. You have had tender passages, which you would not desire me to read aloud: the tears start at their memory. If your life were written, you would say, “Let these not be told; they were only between God and my soul”-some chaste and blessed love passages between you and Christ, which must not be revealed to men. Have you forgotten how then you said, “I am my Beloved’s, and He is mine,” and what you promised when you saw all His goodness made to pass before you. I have now to stir up your pure minds by way of remembrance and bid you present unto the Lord the double offering of your heart’s praise and of your performed vow. “O magnify the Lord with me and let us exalt His name together.” ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/1023.cfm