Tafsir of Ar-Rum 30:22

(And of His signs is the creation of the heavens and the earth, and the diversity of your tongues): Meaning your languages, in that He—Glory be to Him—taught every species its language, or He—Exalted and Majestic is He—inspired them with its invention and empowered them for it. Thus, some speak Arabic, some Persian, some Roman, and others beyond that, the number of which is known only to Allah the Almighty.

Wahb reported that there are seventy-two languages: seventeen among the descendants of Ham, nineteen among the descendants of Sam, and thirty-six among the descendants of Japheth. It is also permitted that "tongues" refers to the modes and forms of speech, for these vary so greatly that one can hardly find two speakers who are equal in quality in every respect. Perhaps this is more appropriate than what preceded it. The Imam [al-Razi] narrated the first interpretation, yet prioritized what is apparent—that what is meant by "tongues" is voices and intonations—and stated that it is more authentic than the one narrated.

(And your colors): [Referring to] the whiteness and blackness of the skin and what lies between them, or the shaping of limbs, their forms, their colors, and their features, such that differentiation occurs between individuals. Even twins, despite the agreement of their materials, their causes, and the conditions they encounter during formation, inevitably differ in something of this, even if they are in the utmost resemblance. "Colors" may also be in the sense of varieties and types, as one says: "colors of speech" and "colors of food." This interpretation is more comprehensive than the first.

The diversity of tongues and colors was organized into the thread of the cosmic signs—alongside the creation of the heavens and the earth—despite it being among the internal (human) signs that are worthy of being organized alongside what preceded it, such as the creation of their own selves and their spouses, to signal its independence and to guard against the illusion that it is merely one of the supplements of their creation.

(Indeed in that): Meaning in what was mentioned of the creation of the heavens, the earth, and the diversity of tongues and colors, (are signs) great and numerous (for those of knowledge): Meaning those described with knowledge, as in the saying of the Exalted: "And none understand them except those of knowledge." Many recited "al-‘ālamīn" (the worlds/all of creation) with the lam vocalized with a fatha, and in this is an indication of the clarity of the signs and their lack of hiddenness to any of the creation at all.