Arabic calligraphy reading "Allahu jalla jalaluhu".  It is closely modelled on the "<a href="//commons.wikimedia.org/wiki/File:Istanbul,_Hagia_Sophia,_Allah.jpg" title="File:Istanbul, Hagia Sophia, Allah.jpg">Hagia Sophia medal</a>" but unlike there, "Allah" is spelled with explicit hamzat al-wasl. This spelling is unusual, not to say unreferenced.
This highly unusual (or wrong?) spelling has now become ubiquitous on Wikipedia via the descendants of this image (and via the usual Wikipedia <a href="https://en.wikipedia.org/wiki/ripoff" class="extiw" title="w:ripoff">ripoffs</a>, on the <a href="https://en.wikipedia.org/wiki/internet" class="extiw" title="w:internet">internet</a> in general)
<a href="//commons.wikimedia.org/wiki/User:Ibrahim_ebi" title="User:Ibrahim ebi">Ibrahim ebi</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>, derived from <a href="//commons.wikimedia.org/wiki/File:Allah.png" title="File:Allah.png">File:Allah.png</a> by same uploader