Tafsir of Ar-Ra'd 13:8

{Allah knows what...}

It is possible that this is a new statement, or that the meaning is: "He is Allah," as an explanation for the "Guide" mentioned in the previous verse. Then, a new sentence begins: {He knows what every female bears}.

The "what" (mā) in {what she bears}, {what the wombs diminish}, and {what they increase} may be relative (mawṣūlah) or infinitive (maṣdariyyah).

If it is relative: The meaning is that He knows what she bears of offspring, in whatever state it may be: male or female, full-term or premature, beautiful or ugly, tall or short, and other present or future conditions.

• {What the wombs diminish}: i.e., what they decrease. It is said: "The water diminished (ghāḍa)," and "I caused it to diminish (ghiḍtuhu)." From this is His saying: {And the water subsided} (Hud: 44).
• {And what they increase}: i.e., what they take in addition. You say: "I took my right from him, and I increased (izdadtu) from him such and such." From this is His saying: {And they added nine} (Al-Kahf: 25). It is said: "I increased it (zidtu-hu), so it increased (zāda) by itself, and it increased (izdāda)."

What the womb diminishes or increases includes:

1. The number of offspring: It may contain one, or it may contain two, three, or four. It is narrated that Sharīk was the fourth of four in his mother's womb.
2. The body of the child: It may be full-term or premature.
3. The duration of gestation: It may be less than nine months or more, up to two years according to Abu Hanifa, four years according to Al-Shafi'i, and five years according to Malik. It is said that Al-Dahhak was born after two years, and Haram ibn Hayyan remained in his mother's womb for four years, which is why he was named Haram (the aged one).
4. The blood: It may decrease or increase.

If it is infinitive: The meaning is that He knows the bearing of every female, and He knows the diminishing and increasing of the wombs; nothing of that, nor its times or conditions, is hidden from Him.

It is permissible that the intent is the diminishing and increasing of what is in the wombs, attributing the action to the wombs while it refers to what is within them, assuming the two verbs are intransitive. This is supported by the statement of Al-Hasan: "Diminishing (ghayḍūḍah) is to deliver at eight months or less, and increasing is to exceed nine months." From this is the "diminishing" which is a miscarriage before term, and the "increasing" which is a birth at term.

{With a measure}: With a single measure that does not exceed it nor fall short of it, like His saying: {Indeed, all things We created with predestination} (Al-Qamar: 49).

{The Grand}: The One of great status, before Whom everything else is insignificant.

{The Exalted}: The One who is exalted above all things by His power, or the One who is too great for the attributes of created beings and is exalted above them.