(63) And Isaac went out walking in the field toward evening and, looking up, he saw camels approaching.

It was stated: Rabbi Yosei, son of Rabbi Ḥanina, said: The practice of praying three times daily is ancient, albeit not in its present form; prayers were instituted by the Patriarchs. ... It was taught in a baraita in accordance with the opinion of Rabbi Yosei, son of Rabbi Ḥanina: Abraham instituted the morning prayer, as it is stated when Abraham came to look out over Sodom the day after he had prayed on its behalf: “And Abraham rose early in the morning to the place where he had stood before the Lord” (Genesis 19:27), and the verb standing means nothing other than prayer, as this language is used to describe Pinehas’ prayer after the plague, as it is stated: “And Pinehas stood up and prayed and the plague ended” (Psalms 106:30). Isaac instituted the afternoon prayer, as it is stated: “And Isaac went out to converse [lasuaḥ] in the field toward evening” (Genesis 24:63), and conversation means nothing other than prayer, as it is stated: “A prayer of the afflicted when he is faint and pours out his complaint [siḥo] before the Lord” (Psalms 102:1). Obviously, Isaac was the first to pray as evening approached, at the time of the afternoon prayer.

And there is no conversation (siha) other than prayer, as it is written, "And Isaac went out to converse in the field" – difficulty from in the Perek of the morning prayer (Brachot 26) they say that Isaac established the prayer of minha, as it is written "And Isaac went out to converse in the field," and conversation does not mean anything other than prayer. And it should be understood that both are necessary, for both inform one another, for in the case of Yitzhak, you would think that he had gone out to speak with someone and not for prayer. Therefore, it teaches "I pour out my complaints before you" to teach that it is the language of prayer. 

(1) AND ISAAC WENT OUT TO MEDITATE. The word la-su’ach (to meditate) means to walk among the trees. 

(2) כי לא המטיר BECAUSE GOD HAD NOT CAUSED IT TO RAIN — And what is the reason that God had not caused it to rain? כי אדם אין לעבוד את האדמה BECAUSE THERE WAS NO MAN TO TILL THE GROUND, and there was, therefore, no one to recognize the utility of rain. When Adam came (was created), however, and he realised that it was necessary for the world, he prayed for it and it fell, so that trees and verdure sprang forth.

And on the topic of prayer, Rabbi Ḥiyya bar Abba said that Rabbi Yoḥanan said: One may only pray in a house with windows, as then he can see the heavens and focus his heart, as it is stated with regard to Daniel’s prayer: “In his attic there were open windows facing Jerusalem” (Daniel 6:11).

Windows – that they cause him to direct his heart as he looks towards the heavens and his heart is humbled.