What is the meaning of the Hadeeth in which the Prophet, sallallaahu ‘alayhi wa sallam, said that seeking knowledge is obligatory for every male and female Muslim? Does "knowledge" here mean Sharee‘ah knowledge or secular knowledge or both?

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.

There is a difference of opinion among Muslim scholars over the authenticity of this Hadeeth. The soundest opinion is that this Hadeeth is Saheeh without the word "female Muslim," at the end as stated by As-Suyooti . Female Muslims are included in this Hadeeth, though, because the Arabic word Muslim includes, by implication, both the male and the female. 

Moreover, there is a difference of opinion among Muslim scholars about the definition of the obligatory knowledge mentioned in the Hadeeth. Qaadhi ‘Iyaadh said that a Muslim must know the basics of Islam, that is, believing in the Oneness of Allaah The Almighty and in the prophethood of Muhammad, sallallaahu ‘alayhi wa sallam, and knowing how to perform Salah (prayer), etc.

On the whole, this Hadeeth means that a Muslim must know the obligatory knowledge that he cannot remain ignorant of, that is, believing in the Oneness of Allaah The Almighty, knowing the Prophet, sallallaahu ‘alayhi wa sallam, and learning how to make Wudhoo’ (ablution), Ghusl (ritual bathing) and Salah, etc. However, it is not obligatory for every Muslim to know the other branches of Sharee’ah knowledge, such as washing a dead person and doing Salah over him.

If a Muslim is a trader, then he must know how to buy and sell so he does not sell prohibited things or deal with Riba (interest, usury). However it is not obligatory for every Muslim to learn medicine, economics, engineering, and so on - it is sufficient for some Muslims only to learn these disciplines.

And Allaah Knows best.