Commentary
وَنُوحًا إِذْ نَادَىٰ مِن قَبْلُ
And (remember) Nuh, when he called (for help) earlier - 21:76
Here مِن قَبْلُ (earlier) means before the time of Sayyidna Ibrahim and Sayyidna Lut (علیہما السلام) ، whose account has just preceded in previous verses. As for the prayer of Nuh علیہ السلام which is referred to here briefly, the version given in Surah Nuh is that Sayyidna Nuh (علیہ السلام) had cursed his people, رَّبِّ لَا تَذَرْ عَلَى الْأَرْضِ مِنَ الْكَافِرِينَ دَيَّارًا (My Lord, leave not upon the earth of the unbelievers even one - 71:26). It is reported at another place that when the people of Nuh (علیہ السلام) did not listen to him at all, he prayed to Allah Ta` ala أَنِّي مَغْلُوبٌ فَانتَصِرْ (I am vanquished; do Thou succour me! - 54:10) so You take revenge from them.
فَاسْتَجَبْنَا لَهُ فَنَجَّيْنَاهُ وَأَهْلَهُ مِنَ الْكَرْبِ الْعَظِيمِ (So, We responded to him and saved him and his family from the terrible agony - 21:76) Here the expression 'terrible agony' either refers to the drowning in the deluge which annihilated the entire people or the torture which he and his followers suffered at the hands of those people.
Allah tells us how He responded to His servant and Messenger Nuh, peace be upon him, when he prayed to Him against his people for their disbelief in him:
(Then he invoked his Lord (saying): "I have been overcome, so help (me)!") 54:10
(And Nuh said: "My Lord! Leave not any inhabitant of the disbelievers on the earth! If You leave them, they will mislead Your servants, and they will beget none but wicked disbelievers) 71:26-27. So Allah says here,
(And (remember) Nuh, when he cried (to Us) aforetime. We answered to his invocation and saved him and his family) meaning, those who believed with him, as Allah says elsewhere:
(...and your family -- except him against whom the Word has already gone forth -- and those who believe. And none believed with him, except a few) 11: 40.
(from the great dis- tress.) meaning, from difficulty, rejection and harm. For he remained among them for one thousand years less fifty, calling them to Allah, and no one had believed in him except for a few. His people were plotting against him and advising one another century after century, generation after generation, to oppose him.
(We helped him against the people) means, `We saved him and helped him against the people,'
(who denied Our Ayat. Verily, they were a people given to evil. So We drowned them all.) meaning, Allah drowned them all, and not one of them was left on the face of the earth, as their Prophet had prayed would happen to them.