In 751, the Abbasid Caliphate defeated the Chinese Tang Dynasty at the Battle of Talas, near the Caspian Sea. In 756, the Abbasids sent 3,000 mercenaries to aid the Tang against the An Lushan Rebellion.
This military engagement, and in particular the reversal of Abbasid alignment (as well as involvement of the Uyghur Khaganate and the Tibetan Empire), suggests an eastward orientation of the Muslim world that seems very surprising to me as we normally only hear about Muslim conflicts with Europeans.
I have searched the subreddit for more information about the Battle of Talas but most are rather superficial and with very few replies.
Edit, quick correction: I realize the Abbasid Caliphate wasn’t founded until the 8th century, so the timeframe in the title question is inaccurate. Were the Abassids more eastward-facing than the Umayyads had been?
There is more to say, but I addressed the issue of Arab-Chinese interaction – which was largely seaborne – during the late Umayyad and early Abbasid periods in a long post some time ago. You might like to review that response while you wait for fresh answers to your query: