What is a word that means both testimony and at the same time reminder?
The act of commemorating or calling to remembrance by some solemnity; the act of honoring the memory of some person or event by solemn celebration: as, the feast of the passover among the Israelites was an annual commemoration of their deliverance from Egypt.
Another possibility here is observance
1. an act or instance of following, obeying, or conforming to: the observance of traffic laws.
2. a keeping or celebration by appropriate procedure, ceremonies, etc.: the observance of the Sabbath.
3. a procedure, ceremony, or rite, as for a particular occasion: patriotic observances.