Abraham's departure marks a dramatic turning point, a moment defined by absolute obedience and burning faith as he leaves his past and family for an unknown future. The primary approach among commentators is that he acts with extraordinary speed. He does not hesitate, ask questions, or wait to organize a caravan, sell his assets, or gather provisions. Instead, he sets out the moment he hears the divine command [אור החיים, העמק דבר, רד״ק, שפתי כהן, קאסוטו]. Beyond the physical journey, this is a profound mental and spiritual separation from his previous environment [מלבי״ם].
Abraham's motivations are entirely pure. He embarks on this journey solely for the sake of heaven and to fulfill the decree of his Creator, ignoring the great rewards and promises offered to him [אור החיים, מלבי״ם, חתם סופר, אלשיך, פרדס יוסף]. He responds exclusively to the absolute, unwavering command of God rather than the softer, more inviting promises of wealth and greatness. He proves the depth of his faith by stepping forward without even knowing his final destination [אור החיים, רש ר הירש].
His nephew Lot joins the journey, but their motivations are fundamentally different. While Abraham acts out of divine obligation, Lot joins on his own personal initiative simply because he wishes to remain close to his uncle and avoid separation [אור החיים, מלבי״ם, ביאור יש״ר, קאסוטו]. Lot's status is entirely secondary; he tags along to observe and learn from Abraham's actions, though he never reaches his uncle's spiritual heights [מלבי״ם, הכתב והקבלה]. Furthermore, because Lot's father died when he was young, he had become Abraham's ward, making his inclusion in the travels a natural outcome [חזקוני, ביאור שטיינזלץ].
The fact that Abraham departs at seventy-five years of age is not a mere chronological detail, but a testament to the magnitude of his trial. Setting out on a nomadic journey to an unknown land is exceptionally difficult for a person of advanced age, which only magnifies his immense dedication [חתם סופר, רש ר הירש, קאסוטו]. Furthermore, calculations reveal that his father Terah is still alive when Abraham leaves. Despite his love for his elderly father, Abraham refuses to allow family attachments to delay his fulfillment of God's command [רד״ק, פענח רזא, ביאור יש״ר, בכור שור, חזקוני].
Historically, some commentators point out that Abraham actually departs from his homeland twice. He first leaves at age seventy, during which time he experiences significant historical and spiritual events, before returning for five years. His departure at seventy-five marks his second and final exit [הטור הארוך, דעת זקנים, חזקוני]. Alternatively, this age carries a deeper, conceptual meaning. The years Abraham lived before recognizing the true faith and achieving spiritual perfection are not counted as true living. Only upon stepping out to fulfill his divine destiny is it considered as though he has truly lived those seventy-five years [מלבי״ם].