The source for our three daily prayers morning, afternoon and evening are referenced in the Torah in three separate places.
Avraham is first. This is the morning prayer. “And Abraham arose early in the morning to the place where he had stood before the Lord.” Genesis, 19:27
Yitz’chak is the second prayer. This is the afternoon prayer.” And Isaac went forth to pray in the field towards evening, and he lifted his eyes and saw, and behold, camels were approaching.” Genesis 24:63
Ya’akov is the third prayer. The evening prayer. “And [Jacob] encountered the place and lodged there because the sun had set, and he took some of the stones of the place and placed [them] at his head, and he lay down in that place.” Genesis 28:11
This is foundation of who we Jews are. This is the basis of our relationship with G-d. These are the men that G-d made a covenant with.