As for `Ad, they were arrogant in the land without right and they said: 'Who is mightier than us in strength?' See they not that Allah Who created them was mightier in strength than them. And they used to deny Our Ayat!
So, We sent upon them a Sarsar wind in days of calamity that We might give them a taste of disgracing torment in this present worldly life. But surely the torment of the Hereafter will be more disgracing, and they will never be helped.
And as for Thamud, We showed them the path of truth but they preferred blindiness to guidance; so the Sa`iqah of disgracing torment seized them because of what they used to earn.
And We saved those who believed and had Taqwa.
Qur'an, Fussilat [41:15-18]
"As for `Ad, they were arrogant in the land without right."
means, they were arrogant, stubborn and disobedient.
"and they said: 'Who is mightier than us in strength?'"
They boasted of their physical strength, and power; they thought that this would protect them from Allah's punishment.
"See they not that Allah Who created them was mightier in strength than them."
Means, do they not realize, when they are showing enmity, that He is the Almighty Who created all things and gave them whatever strength they have, and that His onslaught will be far greater? This is like the Ayah:
"With Hands did We construct the heaven. Verily, We are able to extend the vastness of space thereof." (51:47)
They openly opposed the Almighty and denied His signs and disobeyed His Messenger. Allah said:
"So We sent upon them a Sarsar wind." Some said that this was strongly blowing wind; others said that it was a cold wind. It was also said that it is the wind that makes a noise. The truth that it was all of these things, for it was a strong wind that was an apt punishment for their being deceived by their physical strength. It was also intensely cold, as Allah says:
"with a Sarsar wind!" (69:6), meaning a very cold wind. It also made a furious sound. Additionally, there is a famous river in the east which is called Sarsar because of the noise it makes as it flows.
"in days of calamity" means, consecutive days.
"seven nights and eight days in succession" (69:7). This is like the Ayah:
"on a day of calamity, continuous" (54:19) i.e., the punishment began on a day which was of evil omen for them, and this evil omen continued for them,
"seven nights and eight days in succession" (69:7) until they were destroyed, every last one of them, and their humiliation in this world was joined to their punishment in the Hereafter. Allah says:
"that We might give them a taste of disgracing torment in this present worldly life. But surely the torment of the Hereafter will be more disgracing."
meaning, more humiliating for them.
"and they will never be helped." means, in the Hereafter, just as they were never helped in this world, and they had no one who could protect them from Allah or save them from His punishment.
"And as fir Thamud, We showed them the path of truth"
Ibn 'Abbas, may Allah be pleased with him, Abu Al-Aliyah, Sa`id bin Jubayr, Qatadah, As-Suddi and Ibn Zayd said, "We explained to them." [At-Tabari 21:448 Surah Hud 11:94] Ath-Thawri said, "We called them."
Allah's saying: "but they preferred blindness to guidance;"
means, 'We showed them the truth and made it clear to them through the words of their Prophet Salih, but they opposed him and rejected him, and they slaughtered the she-camel of Allah which He had made a sign for them of the truth of their Prophet.'
"so the Sa`iqah of disgracing torment seized them"
means, Allah sent upon them the Sa`iqah, [See volume five, the Tafser of Surah Hud 11:94] earthquake, intense humiliation, punishment and torment.
"because of what they used to earn" means, because of their disbelief and rejection.
"And We saved those who believed"
means, 'We saved them from among them, and no harm came to them;' Allah saved them along with His Prophet Salih, peace be upon him, because of their fear of Allah.
Tafsir Ibn Kathir (Abridged), Volume 8