tu, not expressed for emphasis but merely to carry the concessive quidem.
Sabinos: Ligarius was of Sabine origin, and many of his Sabine friends were present on this occasion.
fiorem, etc.: the Sabine territory among the mountains was still the home of a hardy and virtuous population.
nosti: during the First Civil War, Caesar had found shelter from Sulla among these kindly mountaineers.
squalorem: it was the custom of the Romans to express their sympathy for one in danger by going into mourning, that is, by wearing ragged and mean apparel. When Cicero was threatened with exile some 20,000 of his friends are said to have appeared in this guise.
