﴿ وَأَنكِحُوا۟ ٱلْأَيَٰمَىٰ مِنكُمْ وَٱلصَّٰلِحِينَ مِنْ عِبَادِكُمْ وَإِمَآئِكُمْ ۚ إِن يَكُونُوا۟ فُقَرَآءَ يُغْنِهِمُ ٱللَّهُ مِن فَضْلِهِۦ ۗ وَٱللَّهُ وَٰسِعٌ عَلِيمٌۭ ﴾

“AND [you ought to] marry the single from among you as well as such of your male and female slaves as are fit [for marriage]. If they [whom you intend to marry] are poor, [let this not deter you;] God will grant them sufficiency out of His bounty - for God is infinite [in His mercy], all-knowing.”

Then Allah guided them to marry their boys and girls, brothers and sisters, who do not have spouses, saying: (And marry such of you as are solitary) your daughters and sisters; and it is said that this means: your children and brothers and sisters who are still unmarried (and the pious of your slaves and maid servants) and also get your pious slave men and women married. (If they) i.e. those who are free (be poor; Allah will enrich them of His bounty) of His provision. (Allah is of ample means) He provides for both those who are free as well as for the slaves, (Aware) and He is Aware of the provision of all of them.