Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:4:21 –

And how could you take it while you have gone in unto each other and they have taken from you a solemn covenant?  

How shall you take it, that is, by what right, when each of you has been privily with the other, through sexual intercourse, which validates the dowry, and they have taken from you a solemn covenant, a binding pledge, and that is what God commanded, namely, that they should be retained honourably or set free virtuously.
القرآن:٤:٢١ –

وَكَيْفَ تَأْخُذُونَهُ وَقَدْ أَفْضَىٰ بَعْضُكُمْ إِلَىٰ بَعْضٍ وَأَخَذْنَ مِنْكُمْ مِيثَاقًا غَلِيظًا  

{وكيف تأخذونه} أي بأي وجه {وقد أفضى} وصل {بعضكم إلى بعض} بالجماع المقرر للمهر {وأخذن منكم ميثاقا} عهدا {غليظا} شديدا وهو ما أمر الله به من إمساكهن بمعروف أو تسريحهن بإحسان.