That no man be moved (to mēdena sainesthai). Epexegetical articular infinitive in accusative case of general reference. Sainō is old word to wag the tail, to flatter, beguile and this sense suits here (only N.T. example). The sense of “moved” or troubled or disheartened is from siainesthai the reading of F G and found in the papyri.
We are appointed (keimetha). Present middle, used here as passive of tithēmi. We Christians are set hereunto (eis touto) to be beguiled by tribulations. We must resist.