The word(s) "basis" appears 6 time(s) in 4 verse(s) in Quran in Mohsin Khan translation.

(1) The divorce is twice, after that, either you retain her on reasonable terms or release her with kindness. And it is not lawful for you (men) to take back (from your wives) any of your Mahr (bridal-money given by the husband to his wife at the time of marriage) which you have given them, except when both parties fear that they would be unable to keep the limits ordained by Allah (e.g. to deal with each other on a fair basis). Then if you fear that they would not be able to keep the limits ordained by Allah, then there is no sin on either of them if she gives back (the Mahr or a part of it) for her Al-Khul' (divorce) . These are the limits ordained by Allah, so do not transgress them. And whoever transgresses the limits ordained by Allah, then such are the Zalimun (wrong-doers).

(2) And when you have divorced women and they have fulfilled the term of their prescribed period, either take them back on reasonable basis or set them free on reasonable basis. But do not take them back to hurt them, and whoever does that, then he has wronged himself. And treat not the Verses (Laws) of Allah as a jest, but remember Allah's Favours on you (i.e. Islam), and that which He has sent down to you of the Book (i.e. the Qur'an) and Al-Hikmah (the Prophet's Sunnah - legal ways - Islamic jurisprudence.) whereby He instructs you. And fear Allah, and know that Allah is All-Aware of everything.

(3) And when you have divorced women and they have fulfilled the term of their prescribed period, do not prevent them from marrying their (former) husbands, if they mutually agree on reasonable basis. This (instruction) is an admonition for him among you who believes in Allah and the Last Day. That is more virtuous and purer for you. Allah knows and you know not.

(4) The mothers shall give suck to their children for two whole years, (that is) for those (parents) who desire to complete the term of suckling, but the father of the child shall bear the cost of the mother's food and clothing on a reasonable basis. No person shall have a burden laid on him greater than he can bear. No mother shall be treated unfairly on account of her child, nor father on account of his child. And on the (father's) heir is incumbent the like of that (which was incumbent on the father). If they both decide on weaning, by mutual consent, and after due consultation, there is no sin on them. And if you decide on a foster suckling-mother for your children, there is no sin on you, provided you pay (the mother) what you agreed (to give her) on reasonable basis. And fear Allah and know that Allah is All-Seer of what you do.