What does Kino try to convince Juana to do, for her safety's sake?

Kino tries to convince Juana to hide while he goes on. In this way, she and the baby will be safe, as the trackers will follow him. Juana refuses.

"Juana," he said, "I will go on and you will hide. I will lead them into the mountains, and when they have gone past, you will go north to Loreto or to Santa Rosalia. Then, if I can escape them, I will come to you. It is the only safe way."