In the Talmud (Shabbos 23:2), it is written:
Omar Rav Huna H’rogil b’ner (he who is used to kindling candles …for Chanukah or Shabbos) …will have children that will be Torah Scholars. H’zohir (he who is carful) b’mezuzah …will have a nice house. H’zohir b’tzitzis …will have nice clothes. H’zohir b’kiddush …will fill many barrels of wine.
Why is the word h’rogil (he who is used to) used in reference to the candles, and h’zohir (he who is careful) is used for the others?
In order to raise children that are talmidei chachomim, it is not enough to be careful (zohir) in performing the mitzvos. We need to be used to them (rogil) by constantly doing them and performing them with a flare and varemkeit (warmth) so that our children see us as a living example and emulate us.
It says that by lighting Chanukah candles, you will have children that will be Torah scholars. There is a hint to this in the way the mitzvah is performed. The mitzvah is to light the candles “ad shetichlah regel min hashuk” – from when it gets dark until the people are no longer walking the marketplace or streets. Torah Scholars don’t walk the streets; they are yoshev ohel they sit indoors and learn Torah.