Fish on Friday night – Ask the Rabbi
Q. We have the custom of eating fish on Friday night. Does this have a historic basis?
A. Friday night is said to be a special time for marital relations, hopefully leading to procreation; fish are a symbol of fertility.
Some people read Shir HaShirim (Song of Songs) on Friday night; as a love story it awakens thoughts of love. Lighting Shabbat candles is thought to be rewarded by producing children dedicated to the Torah (cf. Talmud Shabbat 23b).