There is no harm in wearing the 'Iqal, because the principle in clothing is that it is permissible except for when there is a proof to establish its prohibition. Allaah Almighty censured the one who declares clothing or food forbidden if it is in fact permitted. Allaah Almighty says:
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"Say: Who has forbidden the adornment (with clothes) given by Allaah, which He has produced for His servants, and At-Tayyibat (good things) of sustenance." [Al-A'raf 7:32]
Clothes are forbidden only if a proof states that it is forbidden — like silk for men or clothes that have pictures on them for men and women, or they could be unlawful because of their source, like the case of the clothes that are specific to the disbelievers, which are unlawful. Otherwise the general rule is permissibility
 'Iqal refers to the black cord worn around the headdress by males in many Arab countries.