There are herbs which turn the hair soft and long, but one of the herbs mixed with them turns the hair black. The blackness is a result of using the herbs to soften the hair and it is not meant in itself by the process. What is the Sharee'ah ruling on using these herbs?

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, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

It is permissible for one to comb his hair and use substances which turn it long and soft. All this is included in the command of the Prophet, sallallaahu ‘alayhi wa sallam, to honor one's hair. Abu Hurayrah narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: "Whoever has hair should honor it." [Abu Daawood]

Nevertheless, there are authentic hadiths that warn against dying hair black. Actually, there is a severe threat in this regard, as it was narrated that Jaabir said: "Abu Quhaafah, the father of Abu Bakr was brought on the Conquest of Makkah and his head was very white. The Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said, 'Change it, but avoid black.'" [Muslim]

In another Hadeeth, the Prophet, sallallaahu ‘alayhi wa sallam, said: "At the end of time there will be people who will dye with black like the crops of doves, they will not experience the fragrance of Paradise." [Abu Daawood]

This is in addition to other proofs which forbid this. Principally, the forbiddance means prohibition unless there is a reason to mean undesirability, and there is no reason in this regard. Moreover, the threat reported in the last Hadeeth could not be prescribed but for a prohibited matter or abandoning an obligation, as it is decided by the scholars of Usool Al-Fiqh (Fundamentals of Islamic Jurisprudence).

Consequently, it is permissible to use the aforementioned herbs for the head provided that the type which turns hair black is avoided.

Allaah Knows best.