Rigved is the first ved that was written. And that is not mean before that, there were no written book or they have not knowledge of medicine, singing or mystics. Actually ved is all in one accumulation and rigved is the first one that were written and if first time this type of work you can do you definitely would want to write about more important things, that carry almost all knowledge.And that is why Rigveda contains a lot of information about the creation of this universe and how life goes on over time and what social harmony should be like, and most importantly mantras, hymns, yogas, stories and all. So that a society always can know the real fact of life and this creation and can live wonderfully with mystic power and get liberation.

Let us know more about it, rigved have 10 mondal which have 1028 hymns and each mondal are dedicated to rishi because their main knowledge were used into them and that rishi were vasist, vishwamitra and jagdamini. there were many but as these are seven rishi so Just inform you. Rigved is all about knowledge, so if you want please go through it.