Here Allah consoles His servant and Messenger Muhammad ﷺ by telling him that Nuh, peace be upon him, stayed among his people for this long period of time, calling them night and day, in secret and openly, but in spite of all that they still persisted in their aversion to the truth, turning away from it and disbelieving in him. Only a few of them believed with him. Allah says:

فَلَبِثَ فِيهِمْ أَلْفَ سَنَةٍ إِلاَّ خَمْسِينَ عَاماً فَأَخَذَهُمُ الطُّوفَانُ وَهُمْ ظَـلِمُونَ

(and he stayed among them a thousand years less fifty years; and the Deluge overtook them while they were wrongdoers.) meaning, `after this long period of time, when the Message and the warning had been of no avail, so, O Muhammad, do not feel sorry because of those among your people who disbelieve in you, and do not grieve for them, for Allah guides whomsoever He wills and leaves astray whomsoever He wills. The matter rests with Him and all things will return to Him.'

إِنَّ الَّذِينَ حَقَّتْ عَلَيْهِمْ كَلِمَةُ رَبِّكَ لاَ يُؤْمِنُونَ وَلَوْ جَآءَتْهُمْ كُلُّ ءايَةٍ

(Truly, those, against whom the Word of your Lord has been justified, will not believe. Even if every sign should come to them) (10:96-97). Know that Allah will help you and support you and cause you to prevail, and He will defeat and humiliate your enemies, and make them the lowest of the low. It was recorded that Ibn `Abbas said: "Nuh received his mission when he was forty years old, and he stayed among his people for a thousand years less fifty; after the Flood he lived for sixty years until people had increased and spread."

فأَنْجَيْنـهُ وأَصْحَـبَ السَّفِينَةِ

(Then We saved him and the Companions of the Boat,) means, those who believed in Nuh, peace be upon him. We have already discussed this in detail in Surah Hud, and there is no need to repeat it here.

وَجَعَلْنَـهَآ ءَايَةً لِّلْعَـلَمِينَ

(and made it (the ship) an Ayah for all people.) means, `We caused that ship to remain,' whether in itself, as Qatadah said, that it remained until the beginning of Islam, on Mount Judi, or whether the concept of sailing in ships was left as a reminder to mankind of how Allah had saved them from the Flood. This is like the Ayat: s

وَءَايَةٌ لَّهُمْ أَنَّا حَمَلْنَا ذُرِّيَّتَهُمْ فِى الْفُلْكِ الْمَشْحُونِ - وَخَلَقْنَا لَهُمْ مِّن مِّثْلِهِ مَا يَرْكَبُونَ

(And an Ayah for them is that We bore their offspring in the laden ship. And We have created for them of the like thereunto, on which they ride) until:

وَمَتَاعاً إِلَى حِينٍ

(and as an enjoyment for a while) 36:41-44.

إِنَّا لَمَّا طَغَا الْمَآءُ حَمَلْنَـكُمْ فِى الْجَارِيَةِ - لِنَجْعَلَهَا لَكُمْ تَذْكِرَةً وَتَعِيَهَآ أُذُنٌ وَعِيَةٌ

(Verily, when the water rose beyond its limits, We carried you in the ship. That We might make it an admonition for you and that it might be retained by the retaining ears.) (69:11-12) And Allah says here:

فأَنْجَيْنـهُ وأَصْحَـبَ السَّفِينَةِ وَجَعَلْنَـهَآ ءَايَةً لِّلْعَـلَمِينَ

(Then We saved him and the Companions of the Boat, and made it an Ayah for all people.) This is a shift from referring to one specific ship to speaking about ships in general. A similar shift from specific to general is to be seen in the Ayat:

وَلَقَدْ زَيَّنَّا السَّمَآءَ الدُّنْيَا بِمَصَـبِيحَ وَجَعَلْنَـهَا رُجُوماً لِّلشَّيَـطِينِ

(And indeed We have adorned the nearest heaven with lamps, and We have made such lamps missiles to drive away the Shayatin (devils)) (67:5). meaning, `We have made these lamps missiles, but the lamps which are used as missiles are not the same lamps as are used to adorn the heaven.' And Allah says:

وَلَقَدْ خَلَقْنَا الإِنْسَـنَ مِن سُلَـلَةٍ مِّن طِينٍ - ثُمَّ جَعَلْنَـهُ نُطْفَةً فِى قَرَارٍ مَّكِينٍ

(And indeed We created man out of an extract of clay. Thereafter We made him a Nutfah in a safe lodging.) (23:12-13). There are many other similar examples.