Narrated Abu Huraira:
The Prophet (ﷺ) said, "Allah says, 'The vow, does not bring about for the son of Adam anything I have not decreed for him, but his vow may coincide with what has been decided for him, and by this way I cause a miser to spend of his wealth. So he gives Me (spends in charity) for the fulfillment of what has been decreed for him what he would not give Me before but for his vow."
Narrated Ibn `Umar:
The Prophet (ﷺ) forbade vowing and said, "In fact, vowing does not prevent anything, but it makes a miser to spend his property."
Narrated Sa`id bin Al-Harith:
that he heard Ibn `Umar saying, "Weren't people forbidden to make vows?" The Prophet (ﷺ) said, 'A vow neither hastens nor delays anything, but by the making of vows, some of the wealth of a miser is taken out."
Narrated Ibn `Umar:
`Umar asked the Prophet (ﷺ) "I vowed in the Pre-Islamic period of ignorance to stay in I`tikaf for one night in Al-Masjid al-Haram." The Prophet (ﷺ) said to him, "Fulfill your vow."