A Byzantine patriarch charged Muslims with worshipping a lifeless stone

Evidence

The word of truth stops the mouth of these by the mention of their own peculiar abominations, branding with infamy the heathen with the wickedness and abominations of Gentile sacrifices and fables, making the Jews to blush, not only by reminding them of the frequent lapses of their fathers into idolatry, but, further, of their own opposition to the divine law that made such a boasting of holding… . With respect to the Saracens, since they also seem to be among those who urge these charges against us, it will be quite enough for their shame and confusion to allege against them their invocation which even they make in the wilderness to a lifeless stone, namely that which is called Chobar, and the rest of their vain conversation received by traditions from their fathers as, for instance, the ludicrous mysteries of their solemn festivals. — Sophia Rose Arjana, Muslims in the Western Imagination, 165

Categorization

• QUESTION: The ‘Chobar’ stone invocation attributed to Saracens - worth verifying what actual ritual (pre-Islamic or Kaaba-related) is being distorted here.