Alternative sources for this sermon
(see Bibliography for details of these texts)
The young among you should follow the elders while the elders should be kind to the young. Do not be like those rude people of the pre-lslamic (al-jahiliyyah) period who did not exert themselves in religion nor use their intellects in the matter of Allah. They  are like the breaking of eggs in the nest of a dangerous bird, because their breaking looks bad, but keeping them intact would mean the production of dangerous young ones.
A part of the same sermon
About the autocracy and oppression of the Umayyads and their fate
They will divide after their unity and scatter away from their centre. Some of them will stick to the branches, and bending down as the branches bend, until Allah, the Sublime, will collect them together for the day that will be worst for the Umayyads just as the scattered bits of clouds collect together in the autumn. Allah will create affection among them. Then He will make them into a strong mass like the mass of clouds. Then he will open doors for them to flow out from their starting place like the flood of the two gardens (of Saba') from which neither high rocks remained safe nor small hillocks, and its flow could be repulsed neither by strong mountains nor by high lands. Allah will scatter them in the low lands of valleys and then He will make them flow like streams throughout the earth, and through them He will arrange the taking of rights of one people by another people and make one people to stay in the houses of another people. By Allah, all their position and esteem will dissolve as fat dissolves on the fire.
The cause of tyranny
O' people! If you had not evaded support of the truth and had not felt weakness from crushing wrong then he who was not your match would not have aimed at you and he who overpowered you would not have overpowered you. But you roamed about the deserts (of disobedience) like Banu Isra'il (Children of Israel). I swear by my life that after me your tribulations will increase several times, because you will have abandoned the truth behind your backs, severed your connection with your near ones and established relations with remote ones. Know that if you had followed him who was calling you (to guidance) he would have made you tread the ways of the Prophet, then you would have been spared the difficulties of misguidance, and you would have thrown away the crushing burden from your necks.
Footnotes by translator:
.The implication is that the outer Islam of these people required that they should not be molested, but the consequence of sparing them in this way was that they would create mischief and rebellion.