He is the prophet that was sent to 'Âd ben 'Ewas ben Eram ben Sâm ben Nuh [i.e.ben Shem ben Noah] as it was reported, and Hud (PBUH) is the son of 'Abdullah ben Rabâh ben Khalood ben 'Âd ben 'Ewas ben Eram ben Sâm ben Nuh (PBUH), as mentioned in Safeenat Al-Bihâr [book's name] for Al-Muhaddiþ Al-Qommi, and it is the same as that mentioned in Qisas Al-Anbiyâ' [stories of prophets] for 'Abdul-Wahâb Al-Najjâr. It is reported also that Hud is the son of Shâlikh ben Arfakhshd ben Shem ben Noah (PBUH), so the number of fathers between the messenger and his nation is equal so between them and Shem only two and no more, and for the first report about the fathers of Hud (PBUH) there is more than four fathers obviously. God the Exalted did say: And unto (the tribe of) A'ad (We sent) their brother, Hud. He said: O my people! Serve Allah. Ye have no other God save Him. Will ye not ward off (evil) (Al-A`râf:65), and the meaning, and God knows better, that We sent to 'Âd their brother Hud, and it is a joining for what was before from the story of Noah (PUBH) by God's saying: We sent Noah (of old) unto his people, and he said: O my people! Serve Allah. Ye have no other God save Him. Lo! I fear for you the retribution of an Awful Day (Al-A`râf:59), and God did make them the inhabitants of earth after the people of Noah (PBUH), and God did provide them with large bodies, and it was mentioned that one of them could reach the tallness of seventy to one hundred cubits, and as reported from Abi Ja`far Al-Sâdiq (PBUH): they were like long palm trees, one of them can hit the mountain and break a piece of it. And it was said: as a sign of their might, one man of them can knock of rocks by his hand. and they used to worship idols that they called gods, and for this Hud (PBUH) said to them: Would ye wrangle with me over names which ye have named, ye and your fathers, for which no warrant from Allah hath been revealed? (Al-A'râf:71). They are the people that God destroyed by the fatal wind, and they used to say to Hud (PBUH) when he used to calls them to worship God and worship no other god with Him: We think that you've been under the spell of our gods for calling them with bad names.
When Hud (PBUH) called them to God and to His religion and even exaggerated in his sermons and guiding them and warned them against the Will of the Almighty and His punishment in this life and the after-life, all of that, did not bring anything with them, then God saved the rains from them until aridity became over them so that they can be aware of what happened to them and get back to obey God, but that did nothing to them and their ego increased, and in a speech reported to Al-Sajjâd (PBUH) when someone told him (PBUH) by the purpose of criticism that your grandfather [the prophet Muhammad PBUH] said: our brothers wronged us and we fought them for their wrong, so he (PBUH) said in his answer: woe to you, don't you read the Quran? And unto (the tribe of) A'ad (We sent) their brother, Hud (Al-A'râf:65), And unto Midian (We sent) their brother, Shu'eyb (Al-A'râf:85), And to (the tribe of) Thamud (We sent) their brother Salih (Al-A'râf:73), so they are like them, and they were brothers for them in the tribe and not in religion, and in another reported speech he said to them: So God destroyed A'ad and saved Hud, and destroyed Thamud and saved Salih..etc.
And in Al-Kâfi [a book's name] it is reported from Al-Bâqir (PBUH), that Noah brought tidings for Shem in advance for the coming of Hud and said to him: God will send a prophet called Hud, and he will call his people to God but they will deny him and He will destroy them with the wind, so whoever reaches his days let him believe in him and follow him, and there were prophets between both of them. And in Al-Ikmâl [a book's name] as reported from Al-Sâdiq (PBUH) it is that when Noah was about to die he called his followers and said to them: you have to know that after my death there will be an absence in which tyrants will appear, and God will save you by a viceroy from my descendants called Hud, he has respect and calm look-likes, he looks like me in shape and manner, and from them also (PBUT) [meaning the Household members PBUT]: when Hud was sent, he was a descendant of Shem (PBUH) and the others said who is more stronger than we are so they were destroyed by the wind, and Hud foretold his people about Sâlih (PBUH) and advised them to follow him, and as mentioned from Al-Bâqir (PBUH) that prophets were sent in special and general prophecy, and Hud was sent in a special prophecy to A'ad.