"So travel throughout the land" means: go forth. "For four months"—he says this to the people of the treaty among the polytheists. "And know that you cannot escape Allah"—meaning, outstrip Allah such that He cannot overpower you—"and that Allah will disgrace the disbelievers."
﴿فسيحوا فِي الأَرْض﴾ أَي: اذْهَبُوا ﴿أَرْبَعَة أشهر﴾ يَقُولُهُ لأَهْلِ الْعَهْدِ مِنَ الْمُشْرِكِينَ ﴿وَاعْلَمُوا أَنَّكُمْ غَيْرُ مُعْجِزِي اللَّهِ﴾ سَابِقِي اللَّهَ حَتَّى لَا يَقْدِرَ عَلَيْكُمْ ﴿وَأَنَّ اللَّهَ مُخْزِي الْكَافِرِينَ﴾.
