Tafsir of Ar-Rum 30:21

"And of His signs" — which also signify the Resurrection — "is that He created for you" — that is, for your sake — "from among yourselves mates." The creation of the origin of your mates, Eve, from the rib of Adam (peace be upon him) implies their creation from among yourselves, according to the verification already established. The min (from) is partitive (tab’idiyyah), and "yourselves" is used in its literal sense. It is also possible that min denotes origin (ibtida’iyyah), and "yourselves" is a metaphor for the species; meaning, He created for you from your own species, not from another. It is said that this is more consistent with His saying: "that you may find tranquility in them" — that is, that you may incline toward them. It is said, "He found tranquility in him" when one inclines toward another, for homogeneity is among the causes of harmony and mutual acquaintance, just as difference is among the causes of separation and alienation.

"And He placed between you" — that is, between the spouses, either by giving precedence to men over women in the address, or by the omission of an adverbial phrase conjoined to the aforementioned adverb, meaning: "between you and them," as in His saying: "We make no distinction between any of His messengers." It is said it means between the individuals of the species, or between men and women, though this is contested by His saying: "love and mercy," for these refer definitively to what exists between them through the bond of marriage. That is, He placed between you, by means of the marriage He legislated for you, affection and mercy, without there being any prior acquaintance or established bond between you to justify such mutual sympathy, such as kinship or blood relation. It is said that love and mercy are from Allah (Most High), while fark — the hatred of one spouse for the other — is from Satan.

Al-Hasan, Mujahid, and 'Ikrimah said: "Love" is a metonym for marriage, and "mercy" is a metonym for the child. That love in the sense of affection is a metonym for marriage—i.e., intercourse—due to their necessity, is apparent. As for mercy being a metonym for the child due to their association, it is not free from being far-fetched. Others said: love is for the young woman, and mercy is for the old woman. Others said: love is for the adult, and mercy is for the child. Still others said: they both refer to the intertwining of kinship. All of these, as you can see, are debatable.

"Indeed, in that" — that is, in what was mentioned of their creation from dust, the creation of their mates from among themselves, and the casting of love and mercy (it is a reference to everything that preceded) — "are signs" — great signs whose essence cannot be fathomed, numerous signs whose measure cannot be estimated — "for a people who reflect" upon the intricacies of those acts built upon wisdom. This sentence serves as a concluding affirmation for the content that preceded it, with a warning that what was mentioned is not merely a single sign, but rather contains various signs that require reflection, as indicated by the concluding verse-ending.

At-Tibi mentioned that since the purpose of creating mates, finding tranquility in them, and casting love between spouses is not merely the satisfaction of desire—in which animals participate—but rather the multiplication of offspring and the preservation of the species of those who reflect, whose reflection leads them to knowledge and the worship for which the heavens and the earth were created, it was fitting that "those who reflect" should be the conclusion here.