Our guide Issam showed us an underground tomb on the east side of the Great Pyramid in which was laid to rest a man who was involved in the building of the Great Pyramid at the time of Khufu (Cheops). The inscriptions on the west wall of this tomb were simply breathtaking...and sure enough there is the cartouche of Khufu.....sieve, chick, snake, chick, surrounded by an oval frame. Then, below you see a bird and the letter "t". This stands for "akhet" which means the glow at the horizon before dawn and below these two symbols you see "mr" which is the determinative (contextual) sign for pyramid.
Further below is the sign for libation (the pouring of liquid in memory of a deceased) and presumably the lighting of incense, though the latter I am not sure of.
Some pyramid researchers have doubted that the Great Pyramid was built by Khufu or even during the Old Kingdom. This, despite the fact that there are several cartouches containing the name Khufu in the relieving chambers above the King's Chamber, the so called quarry marks made by the workmen who hewned the stones. Specifically, the most famous of these is in Campbell's chamber and has become subject to great controversy as to its authenticity. Some claim it is a forgery made by those who first opened these spaces in the 19th century. Others say the cartouche is real. Either way, in one of the builders' tomb no more than 300 feet away from the Great Pyramid (indicating he was a higher level construction worker), we have independent evidence that the Great Pyramid was constructed during the same time as Khufu was king and these inscription look very real as you all can see.