By faith Abraham, when he was called, obeyed by going out to a place which he was to receive for an inheritance; and he went out, not knowing where he was going. (11:8)
It was not Abraham’s plan to leave Ur and then Haran, and eventually settle in the land of Canaan. In fact, when he left Ur he had no idea where he was going. He was called by God, and only God knew what was in store for him.
In the Greek, he was called is a present participle, and the translation could be, “when he was being called.” In other words, as soon as he understood what God was saying, he started packing. It was instant obedience. It may have taken several days, or even weeks or months, to make final preparation for the trip, but in his mind he was already on the way. From then on, everything he did revolved around obeying God’s call....