Rabbi David HaLevi Segal, the Taz, was born around 1586 in Ludmir (Volodymyr), Volhynia, the son of Rabbi Shmuel HaLevi Segal. A child prodigy, he is said to have known tractates Bava Kamma, Bava Metzia and Bava Batra by heart at seven. He studied under his elder brother, Rabbi Yitzchak HaLevi, author of the responsa Mahari HaLevi, and married Rivka, daughter of his principal teacher, Rabbi Yoel Sirkis, the Bach; after her death he married the Bach's widowed daughter-in-law. He was also a mohel.

From the age of twenty-three he held various rabbinic posts. He was first rabbi of Potylicz, near Rava-Ruska, where he lived in great poverty, and later lived in Kraków, Brisk and Posen. In 1641 he settled in Ostroh, where he founded a yeshiva and wrote his famous work. During the massacres of 1648-1649 he had to flee to Moravia; he then settled in Lvov and was elected its rabbi in 1654. He sent his son and stepson to meet Shabbetai Tzvi; while they came back impressed, he opposed the movement.

His major work, Turei Zahav (Taz), is a commentary on the Shulchan Aruch, whose part on Yoreh De'ah appeared in Lublin in 1646, the same year as the Shach. Printed in the margin of the code, the Taz is, with the Shach, one of the two great classic commentators on the Shulchan Aruch, and his rulings are authoritative.

He passed away in Lvov on 26 Shevat 5427 (1667) and rests there.