أُحِلَّ لَكُمْ لَيْلَةَ الصِّيَامِ الرَّفَثُ
Intimacy with spouses has been permitted for you during the night of fasting.
The verse expressly permits marital intimacy at night during the fasting period. That permission is the intended message, so it is established by direct wording.
The larger passage also addresses eating and drinking at night and completing the fast until nightfall. The text therefore distinguishes permitted nighttime acts from the daytime obligations of fasting.
The wording gives rise to a further question: if a permitted act occurs near dawn, a person may enter the morning requiring ritual bathing. Does that invalidate the fast? This is addressed by ishārah.