וַיֵּצֵא יִצְחָק לָשׂוּחַ בַּשָּׂדֶה
And Isaac went forth to pray in the field.
Isaac originated the Mincha prayer. Abraham originated the Shacharis prayer, as described in the verse, Abraham got up in the morning where he stood (v. 19:27). The Torah emphasizes Abraham’s erect posture during prayer. In Isaac’s case, the term לָשׂוּחַ parallels a phrase used in Psalms 102:1 – תְּפִלָּה לְעָנִי כִי יַעֲטֹף וְלִפְנֵי יְדֹוָד יִשְׁפֹּךְ שִׂיחוֹ- “a prayer for the afflicted man when he swoons, and pours forth his supplication before God,” לָשׂוּחַ connotes the prayer of a broken man who cannot stand upright.
These two postures reflect two types of prayer. Abraham, who was the paragon of chesed, of expansive kindness, consistently prayed for others. Moses similarly prayed on behalf of the nation in the wake of the Golden Calf incident. The word which introduces Moses’ prayer, וַיְחַל , (Ex. 32:11) has the connotation of a demand: R. Abahu said…Moses seized the Holy One Blessed Be He like a person who seizes his friend by the garment and says before him: ‘Master of the Universe, I shall not release You until You forgive and pardon them.’ (Berachos, 32a) One stands erect while making such a request.
Isaac represented the attribute of gevura, which implies withdrawal, contraction, an inward movement. When one prays not on another’s behalf, but on one’s own, his stance is bent over, stooped, “as a poor man begging at the door.” Isaac’s prayer was therefore made in meekness, while bent over. When Moses prayed to be allowed to enter the land of Israel (Deut. 3:23), the word that is used to describe Moses’ prayer is וָאֶתְחַנַּן, which has the connotation of abject supplication. The תַּחֲנוּן prayer is derived from the wordוָאֶתְחַנַּן .connoting the idea that our request is entirely undeserved, that we have no merits that would justify any request on our own behalf. Hence, the tachanun prayer is recited while bent over.
When Rebecca saw Isaac praying, the verse records: וַתִּפֹּל מֵעַל הַגָּמָל, she “fell” from the camel, a fallen posture reflecting Isaac’s own humility during prayer. (Moriah 1973)