Tafsir of Al-Fath 48:22-23

{And if those who disbelieve had fought you}—meaning the people of Mecca, had they not made peace. It is also said: [it refers to] the allies of the people of Khaybar—{they would have turned their backs in flight} and been defeated.

{The established way of Allah}—this is in the position of an emphatic verbal noun (masdar), meaning: Allah has established the victory of His prophets as a fixed practice. This is [the meaning of] His saying, the Exalted: "I will surely overcome, I and My messengers" (Al-Mujadilah: 21).

{And it is He who withheld their hands from you and your hands from them within [the valley of] Mecca after He let you overcome them. And ever is Allah, of what you do, Seeing.}