# he warned and instructed them

The combination of "warned" and "instructed" is a hendiadys that means "strongly warned" or "strictly instructed." Alternate translation: "he strongly warned them" or he strictly instructed them" (See: [[rc://en/ta/man/jit/figs-hendiadys]])

# them to tell this to no one.

"not to tell anyone." or "that they should not tell anyone." This could be stated as a direct quote. Alternate translation: "them, 'Do not tell anyone.'" (See: [[rc://en/ta/man/jit/figs-quotations]])