prep. at, indicating state or condition (‘at peace’, ‘at bay’); at, towards; at, instrumental (‘at the hands of’)

Dovahkiin, Dovahkiin, naal ok zin los vahriin, wah dein vokul mahfaeraak ahst vaal!
Dragonborn, Dragonborn, by his honor is sworn, to keep evil forever at bay!
(Book, Songs of Skyrim)

But I cannot celebrate his fall. Zu'u tiiraaz ahst ok mah. He was my brother once. This world will never be the same.
Zu'u tiiraaz ahst ok mah. = “I am sad at his fall.”
(Paarthurnax, 0009C20A)

Het nok kopraan do Iglif Iiz-Sos, wo grind ok oblaan ni ko morokei vukein, nuz ahst munax haalvut do liiv krasaar.
Here lies the body of Iglif Ice-Boold, who met his end not in glorious combat, but at the cruel touch of the withering sickness.
(Word Wall for Iiz, Ice Form)

Indicates state, condition, or instrumental (by or with). Also indicates direction, towards. Not used to reference location as in ‘by’ or ‘at’.