COMMENTARY on 66:5
A. Yusuf Ali:

Translation:
It may be, if he divorced you (all), 5536 that Allah will give him in exchange Consorts better than you,- who submit (their wills), who believe, who are devout, who turn to Allah in repentance, who worship (in humility), who are given to fasting 5537 previously married or virgins.
Commentary:

5536  From the case of two in verse 4, we now come to the case of all the Consorts generally, in verse 5. Cf. 33:28-30. Their duties and responsibilities were higher than those of other women, and therefore their failure would also be more serious. This is only hypothetical, in order to show us the virtues expected of diem: faith and devotion, worship and service, readiness for travel or hijrah, whether they were young or old, new to married life or otherwise. From them again the more general application follows-to all women in Islam.

5537  Sa'ihat literally, those who travel about for the Faith, renouncing hearth and home: hence those who go on pilgrimage, who fast, who deny themselves the ordinary pleasures of life. Note that the spiritual virtues are named, in the descending order: submitting their wills (Islam), faith and devotion, turning ever to worship and faith, and performing other rites, or perhaps being content with asceticism. And this applies to all women, maiden girls or women of mature experience who were widows or separated from previous husbands by divorce.

 

Muhammad Asad:

Translation:
[O wives of the Prophet!] Were he to divorce [any of] you, God might well give him in your stead spouses better than you - women who surrender themselves unto God, who truly believe, devoutly obey His will, turn [unto Him] in repentance [whenever they have sinned] worship [Him alone] and go on and on [seeking His goodly acceptance] 9 - be they women previously married or virgins. 10
Commentary:
9  For this rendering of the expression sa'ihat, see note 147 on 9:112, where the same expression occurs in the masculine gender relating to both men and women.
10  I.e., like the actual wives of the Prophet, one of whom ("A'ishah) was a virgin when she married him, one (Zaynab bint Jahsh) had been divorced, while the others were widows. This allusion, together with the fact that the Prophet did not divorce any of his wives, as well as the purely hypothetical formulation of this passage, shows that it is meant to be an indirect admonition to the Prophet's wives, who, despite their occasional shortcomings - unavoidable in human beings - did possess the virtues referred to above. On a wider plane, it seems to be an admonition to all believers, men and women alike: and this explains the subsequent change in the discourse.