"And for divorced women is maintenance according to what is acceptable—a duty upon the righteous. Thus does Allah make clear to you His verses that you might use reason," meaning: so that you may use reason.
Muhammad said: His saying "Haqqan" (a duty) is in the accusative case based on the meaning: "It is incumbent as a duty."
﴿وَلِلْمُطَلَّقَاتِ مَتَاعٌ بِالْمَعْرُوفِ حَقًّا عَلَى الْمُتَّقِينَ كَذَلِكَ يُبَيِّنُ اللَّهُ لَكُمْ آيَاته لَعَلَّكُمْ تعقلون﴾ أَي: لكَي تعقلوا.
قَالَ مُحَمَّد: قَوْله ﴿حَقًا﴾ نصب عَلَى معنى: يحِق حَقًا. [آيَة ٢٤٣ - ٢٤٥]