en_tn/luk/05/14.md

to tell no one

This is an indirect quote. It can also be translated as a direct quote "Do not tell anyone." The implied information is "that you have been healed." (See: rc://en/ta/man/translate/figs-quotations, rc://en/ta/man/translate/figs-explicit)

sacrifice for cleansing

The law required a person to make a specific sacrifice after they were cleansed. This allowed the person to be ceremonially clean, and able to again participate in religious rituals.

for a testimony to them

"for a testimony to the priests" or "so that the priests will know that you have truly been healed." The priests in the temple would be confronted with the fact that Jesus had healed the man's leprosy.