Genèse 24:63

And Izhak went forth to pray upon the face of the field at the time of evening; and he lifted up his eyes, and saw, and, behold, the camels were approaching.

ויצא יצחק לשוח בשדה, the word לשוח is basically the same as שיח השדה, “the plants that grow in the field,” (Genesis 2,5). Yitzchok went out to plant useful vegetation, trees, etc., and to check the work of his employees. While he was thus occupied he happened to espy גמלים באים, camels approaching. He came closer to see if per chance they were the camels belonging to his father which the servant Eliezer had been leading.

ויצא יצחק לשוח, he had detoured from his regular path to the field in order to pour out his heart to G’d in prayer. He did not want to be interrupted in his devotion by passing travelers whom he would have to greet. This was in spite of the fact that he had already prayed in Beer lachay Ro-i. His prayer had been answered already, in accordance with Daniel 10,12 מן היום אשר נתת את לבך להבין ולהענות...נשמעו דבריך, “for from the first day you set your mind to get understanding, practicing abstinence before your G’d, your prayer was heard and I have come because of your prayer.”

והנה גמלים באים, when he had gone out to pray, the camels were already headed in his direction. This is what Rivkah referred to when she asked about the man walking “toward us?” (verse 65) This is because when Yitzchok returned from Beer lachay Ro-i to his house he was walking from the north to the south. People coming from Charan (Aram Naharaym) headed for Avraham’s house would be traveling from the east to the west. This is why after having deviated from his route which would have taken him from north to south, and walking in an easterly direction instead, Yitzchok would be walking in the direction from which the camels were approaching, from the land known also as ארץ בני קדם the land belonging to the people of the East. He had reason to believe that Rivkah would come from that direction.

ויצא יצחק, he left the town where he had spent the night. He went without knowing it, on the same route that Rivkah his wife to be was traveling on the way to meet him. He had gone out

לשוח בשדה, to walk among the bushes,

לפנות ערב, at the time when the sun turns down towards the horizon. This is the time of day when many people go for a walk among the shrubs and bushes. While he was thus walking, he raised his eyes looking further along the route he was walking on and he saw גמלים באים, and he veered off his path to walk toward them to check if this was Avraham’s servant Eliezer who was walking at the head. This is what Rivkah meant when she referred to the man who was walking לקראתנו, (verse 65). ותשא, she thought that possibly the man approaching might be Yitzchok; this is why she asked the servant, to find out if her assumption was correct.