en_tn/luk/01/07.md

But

This contrast word shows that what follows here is the opposite of what is expected. People expected that if they did what was right, God would allow them to have children. Although this couple did what was right, they did not have any children.

they were both advanced in their days

This is a euphemism that says that they were very old. Alternate translation: "they had both lived many days" or "they had both lived many years" or "they were both very old" (See: rc://en/ta/man/translate/figs-euphemism)