The ending of Mark, ‘And they (the women) said nothing to anyone for they were afraid’ (16.8) is one of the most famous cruxes in the New Testament. Could the author really have intended to complete the gospel in such a way? Building on a suggestion made by Joel Marcus and Benoit Standaert, this article defends the hypothesis that Mark is deliberately making a reference to Genesis 18.15 LXX. The same rare expression ἐφοβήθη γάρ which has the verb ‘to be afraid’ followed by the preposition γάρ, appears in a comparable context. In both cases, one or more women are presented by God or his messengers with what could appear to be an unlikely promise and a radical impossibility: the birth of a child in old age or the resurrection of a dead person. While presenting a critique of S. Hultgren's recent proposal that Dn 10 is the background of Mark, the approach here is to add an argument based on a scriptural allusion, which Mark was perfectly capable of making, in support of the now predominant view, but still with many critics, that the writer fully intended to end his gospel with 16.8b.