al-Kahf 18:109-110

"Say: 'If the sea were ink for the words of my Lord, the sea would run out before the words of my Lord ran out.' Say: 'I am only a human being like you; it is revealed to me.'"

The first verse gives the same idea as Luqmān 31/27 (the trees as pens, the sea as ink) and it was treated there: inexhaustibility is measured against a countable material. I rely on that treatment.

The two verses may be compared:

The second verse begins word for word like Fuṣṣilat 41/6: qul innamā anā basharun mithlukum yūḥā ilayy. It was treated there and it was recorded there: the answer says that the distance between them does not lie between the two parties. I do not repeat it here.

And the closing sentence of the sūra is worth recording: fa-man kāna yarjū liqāʾa rabbihi fa'l-yaʿmal ʿamalan ṣāliḥan wa lā yushrik bi-ʿibādati rabbihi aḥadā.

I record this as my own reading, and its support is the sūra as a whole: across four stories the limit of knowledge was recounted — the length of time is not known, the ground is not known, the end is not known. And at the close, what is to be done in the midst of what is not known is given in two clauses: righteous deeds, and associating no one with God.

And the word aḥadā must be recorded: the sūra ends with this word — and the same word was the last word of the twenty-second verse too (wa lā tastafti fīhim minhum aḥadā). The sūra is sealed twice with the same word.