。
You must not look down on the poor.
Literal
Poor person [object-を] looking-down-on [must-not-てはならない].
さげすむ is a native Japanese verb meaning 'to look down on, to scorn.' Japanese has a rich set of synonyms for contempt — 軽蔑する, ばかにする, 見下す, 愚弄する, さげすむ — each with slightly different register and nuance. てはいけない is the standard prohibition.