Every family has a story it tells to the outside world. Abraham's was quieter than most. In Targum Pseudo-Jonathan on Genesis 20:13, he finally explains to Abimelech why he left the house of Terach: they tried to turn him toward pulchana nukhraya, foreign worship, and he walked away.
The biblical Hebrew simply says, when God caused me to wander from my father's house. The Targum sharpens the verb. Abraham did not drift. He was pushed — pressed toward idolatry — and he refused. The flight to a new land begins as a flight from the altar of his father.
The arrangement with Sarah comes next. In every place to which we come, say concerning me, He is my brother. The Targum of Pseudo-Jonathan preserves the agreement without softening its strangeness: two people walking a hostile world, staying alive by telling half the truth.
The Maggidim taught that Abraham's first act of faith was not obedience to a command. It was the courage to leave behind the gods of his household. Before he could hear the voice in Genesis 12, he had to silence the voices at home.