I have been doing a little research on the inscription and with the help of Omani friends and colleagues; we have a fair translation. Please correct me if I have got the translation totally wrong (I don’t think I have but who knows) 3rd of Dhu AlHijjah 1237 H is 23/08/1822 G.
“On Thursday the 3rd of Dhu AlHijjah 1237 Hijri the scholar father of Nabhan. Jaiid bin Khamis bin Mohammed bin (?) bin Zaid bin Mansour Al Kharoosi Al Abadhi Al Omani has died. Written by his son Khamis”
But why it was inscribed high up on a rock in the dark entrance to a narrow wadi, we are not sure, it could be that this is where he died….?
He was a very famous Omani scholar of the Ibadi religion.