Ibn ‘Abbaas' statement regarding sun setting in water spring
30-11-2016 | IslamWeb
Question:
Assalaamu alaykum. I am the same questioner of fatwa no. 2633142. Is it true that Ibn ‘Abbaas, may Allaah be pleased with him, held the belief that the sun sets in a spring?
Answer:
All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
In his book As-Saheeh Al-Masboor min At-Tafseer bil Ma'thoor [3/323], the versed scholar Dr. Hikmat Basheer said, “At-Tabari cited in his Tafseer (exegesis) on the authority of Al-Hasan that ‘Ali ibn Abi Talhah narrated that Ibn ‘Abbaas said, 'He found it setting in a hot spring of water.'”
This is a reference to the spring mentioned in the verse (which means): {Until, when he reached the setting of the sun, he found it (as if) setting in a spring of dark mud...} [Quran 18:86]
We do not know of any text narrated on the authority of Ibn ‘Abbaas, may Allah be pleased with him, stating that the sun sets into a spring of water. Rather, it is established to scholars that the sun is larger than the Earth and it cannot possibly set into a spring of water. Rather, it means that it disappears from the sight of the onlooker in that place. Ibn Katheer 
wrote, “The verse means that he followed a route until he reached the furthest point that could be reached in the direction of the sun’s setting, which is the west of the earth, and he saw the sun setting into the ocean from his standpoint. This is something which everyone who goes to the coast can see; it looks as if the sun is setting into the sea, but, in fact, it never leaves its orbit in which it is fixed.” [Tafseer Ibn Katheer]
Al-Qurtubi wrote, “It is not meant that he reached the sun itself in the east and west until he touched it, because it is in space around the earth without touching it, and it is too great to enter any spring on earth. Rather, it is many, many times bigger than the earth. What is meant is that he reached the end of populated land east and west, so he found it – according to his vision – setting in dark water, like when we watch it on flat land, it is as if it enters inside the land...”
As-Sa‘di wrote, “Allah, The Exalted, blessed him with the means to reach the place of the setting of the sun, where he saw it setting as if it was setting into a black, muddy, hot spring according to the perception of his eyes, in the same way that the beholder would see the sun setting into the sea if the sea was between him and the western horizon, although it is very high in the sky.” [Tayseer Al-Kareem Ar-Rahmaan fi Tafseer Kalaam Al-Mannaan]
Also, please refer to fatwa 315658.
Allah knows best.