(46:21) And mention, [O Muhammad], the brother of ‘Aad, when he warned his people in the [region of] al-Ahqaf – and warners had already passed on before him and after him – [saying], “Do not worship except Allah. Indeed, I fear for you the punishment of a terrible day.”
Muhammad Taqi-ud-Din al-Hilali and Muhammad Muhsin Khan,
(46:21) And remember (Hud) the brother of ‘Ad, when he warned his people in Al-Ahqaf (the curved sand-hills in the southern part of Arabian Peninsula). And surely, there have passed away warners before him and after him (saying): “Worship none but Allah; truly, I fear for you the torment of a mighty Day.”
Mohammed Marmaduke William Pickthall
(46:21) And make mention (O Muhammad) of the brother of A’ad when he warned his folk among the wind-curved sandhills – and verily warners came and went before and after him – saying: Serve none but Allah. Lo! I fear for you the doom of a tremendous Day.
Abdullah Yusuf Ali
(46:21) Mention (Hud) one of ‘Ad’s (own) brethren: Behold, he warned his people about the winding Sand-tracts: but there have been warners before him and after him: “Worship ye none other than Allah: Truly I fear for you the Penalty of a Mighty Day.”
Mohammad Habib Shakir
(46:21) And mention the brother of Ad; when he warned his people in the sandy plains,– and indeed warners came before him and after him– saying Serve none but Allah; surely I fear for you the punishment of a grievous day.
Dr. Ghali
(46:21) And remember the brother of Aad, as he warned his people beside (i.e; in the valley of) the Sand Dunes and already warnings had passed away even before him, and even behind him, (saying), “Do not worship anybody except Allah! Surely I fear for you the torment of a tremendous Day.”
Ali Unal
(46:21) Make mention of (Hud) the brother of Ad: he warned his people in al-Ahqaf as indeed warners came and went before and after him (to warn their peoples) saying: “Worship none but God alone. I surely fear for you the punishment of an awesome day.”
Amatul Rahman Omar
(46:21) And make mention of the kinsman of `âd (- Hûd, a Messenger of God to them), when he warned his people (living) in wind-curved sand-dunes (in Hadzramût, south of Arabia) to whom Warners had already come before him and after him (saying), `Worship none but Allâh. I, indeed, fear lest the agony of a dreadful day should befall you.´
Literal
(46:21) And remember Aad`s brother when He warned/gave notice (to) his nation by the long winding sand (patterns/dunes), and the warnings/notices had past/expired from between his hands and from behind him (the warnings were given before and during his time): “That you not worship except God, that I, I fear on (for) you a great day`s/time`s torture.”
Ahmed Ali
(46:21) Remember (Hud) the brother of ‘Ad. When he warned his people in Ahqaf — though many a warner had come and gone before and after him: “Do not worship any one but God, for I fear the punishment of an awful day for you,”
A. J. Arberry
(46:21) And remember the brother of Ad, when he warned his people beside the sand-dunes — and already warners had passed away alike before him and behind him — saying, ‘Serve none but God! Truly I fear for you the chastisement of a dreadful day.
Abdul Majid Daryabadi
(46:21) And remember thou the brother of the Aad when We warned his people in the sandhills – and surely there have passed away warners before him and after him – saying: worship none save Allah, verily I fear for you the torment of a mighty Day.
Maulana Mohammad Ali
(46:21)-
Muhammad Sarwar
(46:21) (Muhammad), recall the brother of the people of Ad, when he warned his people in the valley of al-ahqaf saying, “There existed many warners before and after him. Do not worship anything other than God. I am afraid for you about the torment of the great Day”.
Hamid Abdul Aziz
(46:21) And mention the brother of A´ad; when he warned his people in the wind-curved sand-hills – and indeed Warners came before him and after him – saying, “Serve none but Allah; surely I fear for you the punishment of a grievous day.”
Faridul Haque
(46:21) And remember the fellowman of the tribe of Aad
Talal Itani
(46:21) And mention the brother of Aad, as he warned his people at the dunes. Warnings have passed away before him, and after him: Worship none but God; I fear for you the punishment of a tremendous Day.
Ahmed Raza Khan
(46:21) And remember the fellowman of the tribe of Aad; when he warned his nation in the Ahqaf* and indeed Heralds of warning passed away before and after him that, Do not worship anyone except Allah; indeed I fear the punishment of a Great Day upon you. (* A country among sand dunes.)
Wahiduddin Khan
(46:21) Tell of the brother of ‘Ad; when he warned his people in the sand dunes — and indeed warners came and went before him and after him — saying, “Worship none but God; surely I fear for you the punishment of an awful Day,”
Safi-ur-Rahman al-Mubarakpuri
(46:21) And remember the brother of `Ad, when he warned his people in Al-Ahqaf. And surely, warners had already passed on before him and after him (saying): “Worship none but Allah; truly, I fear for you the torment of a mighty Day.”
Ali Quli Qarai
(46:21) And mention [Hud] the brother of Ad, when he warned his people at Ahqafand warners have passed away before and after himsaying, Do not worship anyone but Allah. Indeed I fear for you the punishment of a tremendous day.
Hasan al-Fatih Qaribullah and Ahmad Darwish
(46:21) Remember Aad’s brother who warned his nation in (the valley of) Al Ahqaf. Warners had already preceded and succeeded him saying: ‘Worship noneexcept Allah! (he said) ‘Indeed, I fear for you the punishment of a Dreadful Day’
That is translated surah Al Ahqaf ayat 21 (QS 46: 21) in arabic and english text, may be useful.