Georstu

According to the Old English Dictionary:

georstu

Oh:--Georstu Dryhten gefreá sáwle míne O Domini libera amimam meam, Ps. Srt. 114, 4: 115, 16: 117, 25. [From (?) gehéres þú. Cf. gehéresthú heus, Wrt. Voc. ii. 110, 26; and for a similar interjectional use cf. sehðe ecce, Ps. Srt. 32, 18; 38, 6.] georstu