Why do words like "salah" and "riba" have an extra unpronounced letter waw in them?

The presence of an extra unpronounced letter "waw" in words like "salah" and "riba" can be understood through the rules of Arabic grammar and phonetics. In Arabic, this phenomenon is often related to the way certain words are derived and their morphological structure.

In Arabic morphology, the "waw" can serve as a marker for specific grammatical functions, such as indicating the connection between roots and patterns. The "waw" in these words is not pronounced but plays a role in forming the structure of the word itself. For example, "salah" can refer to prayer, and the structure of the word reflects its roots and grammatical rules.

Regarding "riba," which means usury or interest, the presence of the "waw" aligns with the phonetic rules of Arabic that govern how certain letters interact with the vowels and other consonants in the word. This structural characteristic is essential for maintaining the integrity of the word as it is used in the language.

While the Qur'an does not explicitly address the phonetic details of these words, it does emphasize the importance of proper speech and pronunciation in several verses. For instance, the Qur'an states: And We have certainly made the Qur'an easy to remember. So is there anyone who will remember? 54:17. This verse highlights the significance of accurately preserving and pronouncing the words of the Qur'an, which extends to the principles of the Arabic language as a whole.

In summary, the extra unpronounced "waw" in words like "salah" and "riba" serves a grammatical purpose within the Arabic language, reflecting its morphological structure and phonetic rules.