其心志

their minds are focused

The character 志 zhì, which is usually a noun meaning "will" or "intent," seems out of place here. Many commentators think it must be a mistake and replace it with 忘 wàng, "forget," which makes a lot more sense. Evidently the mistake, if it was a mistake, was there in our earliest editions, since Guo Xiang struggle to explain it as 所居而安, "comfortable where they live."

On the other hand, this is about where this section takes a turn to the right and starts speaking in terms of traditional Confucian virtue; so perhaps there is something going on here.