(Verses 62 and 63.) And he himself dwelt in the land of the south: and Isaac went forth to meditate in the field towards evening. The land of the south signifies Gerar, to which he had once been led by his father to be sacrificed. But when it says, And he went forth to meditate in the field, which in Greek is called ἀδολεσχῆσαι, in Hebrew it is read: And Isaac went forth to speak in the field, the evening already declining. That signifies, according to what the Lord alone prayed on the mountain, even Isaac, who in the type of the Lord, as a just man going out of his house, offered spiritual victims to God either at the ninth hour or before sunset.
Source: Hebrew Questions on Genesis