What is the name of the collection of hymns, chants, and ritual instructions of the ancient aryans?

   The answer is Vedas.

   I hope this helps you

Vedas

Explanation:

This is the most ancient Hindu scriptures. It was written in early Sanskrit and contained hymns, philosophy, and guidance on ritual for the priests of Vedic religion. Who were believed to have been directly revealed to seers among the early Aryans in India.

I could be wrong, but I'm pretty sure this is the answer.

islam spread slowly through much of africa through trade and preaching.