Calligraphy at Lodhi Gardens

The Bara Gumbad (Big Dome) and Sheesh Gumbad at the Lodhi Gardens in Delhi have the most breathtakingly beautiful calligraphy engraved on their walls. This past July I was in Delhi. I had to meet someone at the India International Center but had a few minutes to spare. The Lodhi Gardens are right behind the IIC. I took a stroll there and even with my amateur photography skills took shots below (click on the picture to enlarge). I presume these are Quranic inscriptions, but I am not sure. Perhaps someone visiting here could help with that...