Al-Ahqaf: the plural of Haqf, which is a high, elongated sand dune that has a curve. The term comes from the root 'haqafa', meaning to bend or curve. The people of 'Aad were known as the 'People of the Pillars', residing between sands overlooking the sea in a land called Al-Shahr in Yemen. It is also said they were between Oman and Mahra. The word 'nudhūr' is the plural of 'nadhir', meaning the one who warns or the warning, from 'between his hands' and 'behind him' and 'after him'. It has been recited as 'from between his hands and from after him'. The meaning is that Hud, peace be upon him, warned them, saying: 'Do not worship except Allah; I fear for you the punishment.' He informed them that the messengers who were sent before him and those who will be sent after him are all warners similar to his warning. According to Ibn Abbas, may Allah be pleased with him, this refers to the messengers who were sent before him and those who were sent in his time. The meaning of 'and from behind him' in this interpretation refers to after his warning, if it is connected. The warnings have been fulfilled by his saying: 'He warned his people.' You may consider Allah's saying 'and indeed the warnings have passed from between his hands and from behind him' as an interruption between 'he warned his people' and 'that you should not worship'. The meaning would be: and remember Hud's warning to his people about the consequences of polytheism and the great punishment, and that those who preceded him among the messengers and those who came after him warned similarly, so remember them.