What happens that makes Crusoe say his fathers earlier prophecy had "come to pass"?

Robinson is apprehended and made a slave.

However, to cut short this melancholy part of our story, our ship being disabled, and three of our men killed and eight wounded, we were obliged to yield, and were carried all prisoners into Sallee, a port belonging to the Moors.

The usage I had there was not so dreadful as at first I had apprehended, nor was I carried up the country to the emperor’s court, as the rest of our men were, but was kept by the captain of the rover as his proper prize, and made his slave, being young and nimble, and fit for his business. At this surprising change of my circumstances from a merchant to a miserable slave, I was perfectly overwhelmed; and now I looked back upon my father’s prophetic discourse to me, that I should be miserable, and have none to relieve me, which I thought was now so effectually brought to pass, that it could not be worse; that now the hand of Heaven had overtaken me, and I was undone without redemption. But alas! this was but a taste of the misery I was to go through, as will appear in the sequel of this story.