'A spiritual recharging of batteries'

''Rabbinical law hangs on a slender hair,'' Rabbi Colin Eimer said, as he explained the celebration of the Jewish Sabbath to a group of religious education teachers attending an evening course on religious festivals at the Regional Religious Education Center, Isleworth.

''Much of our worship springs from long tradition, and most Jewish families see the Sabbath observance as a duty and an obligation to be fulfilled.''

Rabbi Eimer and his charming wife brought along their two little children, aged 2 and 3, to show the teachers how the Jewish holy day meal would be taken at dusk on the Friday evening before the Sabbath Day.

Ready for the Kiddush, the blessing pronounced at the beginning of the Sabbath Eve meal, the table had been set with finest white linen, traditional candlesticks, and, under a cloth, two loaves of plaited bread, the Callah.

The Callah commemorates the two portions of manna gathered by the children of Israel in the wilderness the day before the Sabbath, in preparation for the holy day of rest, with its cessation of work.

The children helped light the candles and joined in the hymns of blessing to God. The silver goblets were filled with wine, specially blessed. This was followed by a family meal including specially prepared food. A hymn of Shalom, or peace, followed.

Rabbi Eimer explained that the family attends synagogue on the Sabbath but no work is done; families may visit relatives, or just relax at home. ''A sense of timelessness needs to be achieved: We break from the bondage of work. It is a sort of spiritual recharging of batteries,'' he said. ''Every family will celebrate the Sabbath in its own way, and some are more orthodox than others. We ourselves would only use the car to visit family friends, and we would not spend money on the Sabbath.''

The teachers learned that at sunset on the Sabbath the candles are blown out and the blessing to Elijah follows, symbolizing the Coming of the Messianic Age. A plaited candle is lighted and extinguished in wine, and a spice box is handed around so that the odor of the Sabbath is taken into the next week. A blessing for a happy week follows, which includes the repetition of Psalm 91.

The presentation of Jewish customs by a rabbi and his family is one of a series sponsored by the center. Christian, Buddhist, Muslim, and Hindu rituals are also demonstrated to make teachers aware of the similarities and differences in the major world religions.