יִרְדְּפֵ֖ם יַעֲב֣וֹר שָׁל֑וֹם אֹ֥רַח בְּרַגְלָ֖יו לֹ֥א יָבֽוֹא׃
他追趕他們，平安地前行，走過他腳從未踏過的路。
Rashi
He pursued them and passed on safely He traversed all his fords safely; he did not stumble when he pursued them.
Ibn Ezra
ירדפם He will pursue them,7A. V., He pursued them. the kings. And pass in peace, that is, without weariness. ארח ברגליו לא יבוא As if he had not at all gone that path with his feet.8That is, As if he had not had the exertion of travelling so far.—A. V., Even by the way that he had not gone with his feet.
Rashi
a path upon which he had not come with his feet A road upon which he had not come previously with his feet. [The future tense of] יָבוֹא means that he was not accustomed to come.