John Calvin Commentary Genesis 24:63

"And Isaac went out to meditate in the field at the eventide. And he lifted up his eyes, and saw, and, behold, there were camels coming." — Genesis 24:63 (ASV)

And Isaac went out. It appears that Isaac lived apart from his father, either because the family was too large, or because such was the custom. Perhaps Abraham had already married another wife, so that, for the sake of avoiding disputes, it would seem more convenient for him to have a house of his own.

Thus, great wealth has its attendant troubles. Doubtless, of all earthly blessings granted by God, none would have been sweeter to Abraham than living with his son. However, I by no means think that he was deprived of his son's company and assistance. For such was the piety of Isaac that he undoubtedly made it his aim to fulfill every duty towards his father; this alone was lacking: they did not live in the same house.

Moses also relates how Isaac met his wife before she reached his home. For he says that Isaac went out in the evening to meditate or to pray. The Hebrew word שוח (soach) can mean either. It is probable that he did this according to his custom, and that he sought a place of retirement for prayer, so that his mind, being released from all distractions, might be freer to serve God. Whether, however, he was giving his mind to meditation or to prayer, the Lord granted him a sign of His own presence in that joyful meeting.