Final answer:
The hymn 'Maoz Tzur,' sung after lighting the Chanukah candles, celebrates Jewish religious freedom and the miracle of the oil.
Step-by-step explanation:
After lighting the Chanukah candles, it is a customary tradition to sing the hymn 'Maoz Tzur' (Rock of Ages). This song is sung in celebration and commemoration of the Jewish people's historical struggle for religious freedom and the miracle of the oil that occurred during the rededication of the Holy Temple in Jerusalem. The lyrics of 'Maoz Tzur' express gratitude and praise for deliverance from oppression and hardship.