The Quran

هُمُ الَّذينَ كَفَروا وَصَدّوكُم عَنِ المَسجِدِ الحَرامِ وَالهَديَ مَعكوفًا أَن يَبلُغَ مَحِلَّهُ ۚ وَلَولا رِجالٌ مُؤمِنونَ وَنِساءٌ مُؤمِناتٌ لَم تَعلَموهُم أَن تَطَئوهُم فَتُصيبَكُم مِنهُم مَعَرَّةٌ بِغَيرِ عِلمٍ ۖ لِيُدخِلَ اللَّهُ في رَحمَتِهِ مَن يَشاءُ ۚ لَو تَزَيَّلوا لَعَذَّبنَا الَّذينَ كَفَروا مِنهُم عَذابًا أَليمًا

Muhammad Asad

[It was not for your enemies' sake that He stayed your hands from them:¹ for] it was they who were bent on denying the truth, and who debarred you from the Inviolable House of Worship² and prevented your offering from reaching its destination.³ And had it not been for the believing men and believing women [in Mecca], whom you might have unwittingly trampled underfoot,⁴ and on whose account you might have become guilty, without knowing it, of a grievous wrong -: [had it not been for this, you would have been allowed to fight your way into the city: but you were forbidden to fight⁵] so that [in time] God might admit to His grace whomever He wills.⁶ Had they [who deserve Our mercy and they whom We have condemned] been clearly discernible [to youj,⁷ We would indeed have imposed grievous suffering [at your hands] on such of them as were bent on denying the truth.

This interpolation is based on Razi's explanation of the connection between this and the preceding verse.
I.e., the Ka'bah, which, until the year 7 H., the Muslims were not allowed to approach.
See surah 2, note 175.
I.e., killed. After the Prophet's and his followers' exodus to Medina, a number of Meccans - both men and women - had embraced Islam, but had been prevented by the pagan Quraysh from emigrating (Tabari, Zamakhshari). Their identities were not generally known to the Muslims of Medina.
Thus Zamakhshari, supported by Razi, Ibn Kathir, and other commentators.
I.e., so that the believers might be spared, and that in time many a pagan Meccan might embrace Islam, as actually happened.
Lit., "had they been separated from one another": i.e., the believers and the pagans among the Meccans. In its wider sense, the above implies that man never really knows whether another human being deserves God's grace or condemnation.