The conquest and settlement of the Promised Land was not designed to be an overnight event. Instead, God planned a slow, measured process to drive out the current inhabitants, ensuring that the Israelites could safely and securely establish their new home. This gradual clearing of the territory created a necessary balance between the reduction of the enemy and the demographic growth of the people.
On a practical level, removing the local nations too quickly would leave vast areas empty and desolate before the Israelites had enough people to populate them [אבן עזרא, קאסוטו]. From a divine perspective, while God used strict justice to drive out the nations using forces like the hornet [רבנו בחיי], the slow pace also offered a window of mercy, giving the inhabitants time to reflect and turn away from their evil actions [ביאור יש״ר].
This measured approach also serves as a practical guide for personal spiritual battles. Attempting to conquer all inner flaws at once often leads to failure. True success requires patience and a systematic process. A person must first tackle the obvious, easier negative traits by subduing their basic physical drives. Only after making that progress can they move on to more delicate internal struggles, eventually lifting their soul to higher spiritual levels [חומש קה״ת].
The success of this gradual settlement depended on the Israelites growing in number, naturally bearing children like fruit on a tree [רש״י, ביאור יש״ר, שטיינזלץ]. The promise of growth here focuses strictly on natural reproduction, omitting language that implies the massive, miraculous population booms the Israelites experienced in Egypt. This specific focus serves as a subtle condition: if the people sin, they will only experience ordinary, natural demographic growth rather than miraculous expansion [משכיל לדוד].
Ultimately, the goal was for the Israelites to spread out and inhabit the territory across its entire length and breadth [ביאור יש״ר, קאסוטו, שטיינזלץ]. The concept of inheriting the land goes beyond simply receiving a plot of earth; it involves deeply taking root and holding on firmly. As families would grow across generations, each person would be able to establish a strong, permanent grip on their personal property, ensuring the entire region was properly and securely settled [שד״ל].