2:270
وَمَا أَنفَقْتُم مِّن نَّفَقَةٍ أَوْ نَذَرْتُم مِّن نَّذْرٍ فَإِنَّ اللّهَ يَعْلَمُهُ وَمَا لِلظَّالِمِينَ مِنْ أَنصَارٍ
And whatever ye spend in charity or devotion, be sure Allah knows it all. But the wrong-doers have no helpers.
19:26
فَكُلِي وَاشْرَبِي وَقَرِّي عَيْناً فَإِمَّا تَرَيِنَّ مِنَ الْبَشَرِ أَحَداً فَقُولِي إِنِّي نَذَرْتُ لِلرَّحْمَنِ صَوْماً فَلَنْ أُكَلِّمَ الْيَوْمَ إِنسِيّاً
"So eat and drink and cool (thine) eye. And if thou dost see any man, say, 'I have vowed a fast to (Allah) Most Gracious, and this day will I enter into not talk with any human being'"
22:29
ثُمَّ لْيَقْضُوا تَفَثَهُمْ وَلْيُوفُوا نُذُورَهُمْ وَلْيَطَّوَّفُوا بِالْبَيْتِ الْعَتِيقِ
"Then let them complete the rites prescribed for them, perform their vows, and (again) circumambulate the Ancient House."
76:7
يُوفُونَ بِالنَّذْرِ وَيَخَافُونَ يَوْماً كَانَ شَرُّهُ مُسْتَطِيراً
They perform (their) vows, and they fear a Day whose evil flies far and wide.