"It is our custom to light a yahrzeit candle in honor of the memory of the Sages, as it is said: “the life breath of man is the lamp of the Lord”. And it is good to add from the light of the Torah to the light of the candle, as it is said “For the commandment is a lamp, the teaching is a light”.
But even a few righteous are also good, and thanks to the sacred Torah and the teachings that Israel will learn in the Sage’s name on the anniversary of his death, the Holy One Blessed be He, will share our part with them, and we will never be ashamed because of our faith in the Holy One Blessed be He, and on his great benevolence and truth will we lean, for He hides his abundant goodness for those who are worthy and revere Him.”
Rabbi Chananaia son of Akashia stated, God wanted to grant merits to Israel, therefore he gave them many laws and commandments as it states, "Because God wants righteousness he increased the amount of Torah and splendor."
