Old School Davening (Berakhot 9b)

The vatikin would complete the recitation of the Shema exactly at sunrise so as to place Redemption right next to Prayer, and one will turn out to say the Prayer in daylight. Said R. Zira, “What verse of Scripture supports this practice? ‘They shall fear you with the sun and before the moon throughout all generations’ (Psa. 72: 5).”

One of the interesting things about the Talmud is the way it reflects evolving Jewish liturgy over half a millennium.   "Redemption" is the final blessing of the Shema, the section of the liturgy represented in our service by Mi Chamocha and Tzur Yisrael.   "Prayer" (Tefila) refers to here not to prayer in general, but to the liturgy also called the Amida ("standing"), and the "18 Benedictions."   In our service, it is represented by the section that begins, "Adonai, open my lips," and concludes with "Sim Shalom."  

We think of Shema and Tefila as two parts of a single service, but in the Talmud they are conceived of as separate acts, each with their own schedule.  The times for the recitation of the Shema are based on the phrase from the Shema itself, "when you lie down and when you rise."  The times for Tefila are based primarily on the sacrificial calendar in the Torah.   Yet the juncture of the two seems natural, almost predestined, and we now do it as a matter of course (although not necessarily at sunrise).

But who are the vatikin?   The academic translations consider them to be unidentified precursors of the Rabbis.  Jacob Neusner translates "the old timers"; Maurice Simon [in the Soncino Talmud] thinks the term "applied to certain men who, in the time of the Hasmonean kingdom, set an example of exceptional piety. Some identify them with the Essenes*."  The yeshiva translations, on the other hand, understand vatikin as simply descriptive of heightened piety: Artscroll translates "devoted"; Steinsaltz, "pious individuals . . . scrupulous" (see also his note on p. 163).  The "scrupulousness" would be reflected in the desire to begin the Tefila right at sunrise.

*Simon is writing before the discovery of the Dead Sea Scrolls, so the speculation is based on accounts of the Essenes in Josephus and Philo.