The people of thy holiness have possessed it but a little while: our adversaries have trodden down thy sanctuary.
The people of thy holiness Israel dedicated as holy unto God (Isaiah 62:12; Deuteronomy 7:6) The people of thy holiness - Israel, dedicated as holy unto God (Isaiah 62:12; Deuteronomy 7:6).
Have possessed (it) but a little while - namely, the Holy Land; or, thy "sanctuary" taken from the following clause, which is parallel to this (cf. Isaiah 64:10-11; Psalms 74:6-8).
Our adversaries have trodden down thy sanctuary - "thy," an argument why God should help them: their cause is His cause.