Based on a legend that the high priest told the eligible men to bring a rod to the temple and the owner of the one that burst into bloom would be Mary's husband. The Holy Spirit in the form of the dove lands on the rod.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/38315261@N00">Sharon Mollerus</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/clairity/42011744392/">Fra Angelico, The Marriage of the Virgin, 1431-35 5/10/18 #gardnermuseum #earlyrenaissance #italy #painting</a>