The invention relates to a releasable retaining device (10) for a tether (16) of an airbag, comprising a retainer (12), a slit (14) for receiving the tether (16), a blocking member (18) made from metal which is displaceable between a blocking position in which it maintains the tether (16) blocked in the slit (14) and a release position in which the tether (16) is released, and comprising a pyrotechnical igniter (20) coupled to the blocking member (18) such that, upon activation of the igniter (20), the blocking member is displaced from the blocking position to the release position. Moreover, a housing (32) including a retaining device (10) for an airbag is provided.