Musnad Ahmad 25:1039

Abu Abd al-Rahman narrated to us, Abdullah ibn Lahi'ah ibn Uqbah al-Hadrami Abu Abd al-Rahman narrated to us, from Abdullah ibn Hubayrah al-Saba'i, from Abd al-Rahman ibn Wa'lah, who said: I heard Ibn Abbas saying: A man asked the Messenger of Allah, peace and blessings of Allah be upon him, about Saba' (Sheba): What is it? Is it a man, a woman, or a land? He said: "Rather, it is a man who fathered ten. Six of them settled in Yemen, and four of them in al-Sham. As for the Yemenis: they are Madh'hij, Kindah, al-Azd, the Ash'ariyyun, Anmar, and Himyar—all of them are Arabs. And as for the Shamis: they are Lakhm, Judham, Amilah, and Ghassan."