What is the meaning of "nafida" (نفد) in the Almighty's saying: "Say, 'If the sea were ink for the words of my Lord, then the sea would surely be exhausted (lan-nafida al-bahr) before the words of my Lord were exhausted'" [Al-Kahf, 109], and what is the difference between it and "nafadha" (نفذ) with a "dhāl" (ذ)?

"Nafid" (نفد) means to perish and be gone. It is not "nafadh" (نفذ) with the ذāl, which means to exit and proceed, as in the Almighty's saying: (مَّا نَفِدَتْ كَلِمَاتُ اللَّهِ) "The Words of Allah would not be exhausted," meaning they would not cease or perish. The meaning of the verse is that Allah's words, wisdom, and signs are immense and never-ending. Even if the oceans were ink and the trees pens for writing, the oceans and pens would be exhausted before the words of Allah are exhausted.