Assalaamu Alaikum wa Rahmatullaahi wa Barakaatuh. Could you please clarify for me what exactly is the hump, the hairstyle like tilted humps of camels that Prophet Muhammad, sallallaahu alayhi wa sallam, told us about in the following Hadeeth: Is it when we tie our hair in a bun and then wear a scarf? "I will not be a witness for two types of people who are destined for the fire: people with whips, like the tails of cows, who beat the people (i.e. tyrants who are the enemies of their own people) and women who, although clothed, are yet naked seducing and being seduced, their hair style like the tilted humps of camels. These will not enter the paradise nor will its fragrance reach them although its fragrance reaches a very great distance." [Muslim]

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

When Imaam An-Nawawi interpreted the narration which you mentioned in the question and which was reported by Imaam Muslim he said: "Their heads will appear like the humps of the Bukht (camels)” means they put a head covering and turbans and other things that are put around the head until she resembles the humps of the Bukht camels.” The Bukht camel is a kind of camels that have great humps, as explained by Ibn Hajar .

As regards the ruling of making the hair in the shape of a bun behind the head, then there are some details about it which were mentioned by Shaykh Ibn ‘Uthaymeen who said: “If the hair is on the upper part of the head, then this is forbidden, but if it is on the neck, then this is permissible unless the woman goes to the market, then in this case, it is considered as a sign of Tabarruj (displaying her beauty and adornment to non-Mahram men) because its shape will appear from under the Abaayah (cloak) and this is Tabarruj and a means of temptation, so this is not permissible.”

The Shaykh mentioned the market just as an example, but what is meant is them going out of their homes in a way that people may see them.

Allaah Knows best.