Musnad Ahmad 30:179

Sufyan narrated to us, from Abu al-Zinad, from al-A’raj, from Abu Hurairah, from the Prophet (peace and blessings of Allah be upon him), who said: "Allah the Almighty and Majestic said: 'A vow does not bring to the son of Adam anything that I have not decreed for him. However, it is a thing by which I extract [charity] from the miser, through which he gives Me what he would not give Me because of his miserliness.'"