Have they not seen how many a generation before them We have destroyed whom We had established on the earth such as We have not established you? And We poured out on them e=rain from the sky in abundance, and made the rivers flow under them. Yet, We destroyed them for their sins, and We created after them other generations.
And even if We had sent down to you (O Muhammad pbuh) a Message written on paper so that they could touch it with their hands the disbelievers would have said: " This is nothing but obvious magic!"
And they say: "Why has not an angel been sent down to him?" Had We sent down an angel, the matter would have been judged at once, and no respite would be granted to them."
(Surah 6: Al-An'am (They Cattle); verses6-8)