Parashat Chayei Sara tells the story of Yitzchak’s marriage to Rivka, the daughter of his first cousin. Avraham assigned his servant the task of finding a suitable mate for Yitzchak, and upon the servant’s return with Rivka, they encountered Yitzchak, who had gone out into the field “la-su’ach” (24:63). The Gemara in Masekhet Berakhot (26b; see also Bereishit Rabba 60:14) interprets this term as a reference to prayer, and thus infers from this verse that Yitzchak instituted the afternoon mincha service. A verse in Tehillim (102:1), as the Gemara cites, speaks of an impoverished man praying, and describes his prayer with the phrase, “yishpokh sicho,” thus suggesting that the term si’ach denotes prayer. Accordingly, the Torah here speaks of Yitzchak as going into the fields to pray. Many commentaries follow the Gemara’s reading, including Rashi, Rabbenu Saadia Gaon, Rabbenu Chananel and Seforno.
The Rashbam and Chizkuni, however, explain this word differently, associating it with the term si’ach used earlier in Sefer Bereishit (2:5, 21:15) in reference to shrubbery. They interpret this verse to mean that Yitzchak had gone into his fields for the purpose of planting and supervising his employees. This excursion was not for prayer, but rather for agricultural work.
Rav Menachem Bentzion Zaks, in his Menachem Tziyon, suggests that we might accept both interpretations, and say that Yitzchak that afternoon both prayed and tended to his fields. In fact, Rav Zaks comments, it is perhaps this precise combination between work and prayer, the responsible concern for both his material and spiritual needs, that impressed Rivka when she set her eyes upon her future husband. The sight of Yitzchak praying alongside his fields reflected the successful fusion of the mundane with the sacred, of one’s material needs with sincere spiritual devotion.
We might add that this image is well-suited for the particular context of the afternoon mincha prayer. What sets mincha apart from the morning and evening prayers is that it takes place in the middle of workday, thus requiring a disruption of one’s professional routine. Whereas shacharit is generally recited before one begins his workday and arvit after the end of the workday, mincha is recited during the afternoon hours, generally when people are still busy at work. Appropriately, this prayer originated with Yitzchak who went out la-su’ach in the field, to both pray and tend to his crops, teaching us the importance of injecting even our mundane pursuits with a spiritual quality.