Commentary for Berakhot 3:3
רבן גמליאל אומר עד שיעלה עמוד השחר.
Rabban Gamliel says: [It may be recited] until the break of dawn.
Rashi on Berakhot
Until dawn - The entire night is called the time of laying down.
Ask RabbiBookmarkShareCopy
Abraham Cohen Footnotes to the English Translation of Masechet Berakhot
According to Maimonides, in his Commentary on the Mishnah, this refers to the first light which becomes visible in the East, about 1 1/5 hours before actual sunrise. Cf. Pesah. 93 b.
Ask RabbiBookmarkShareCopy