Tayammum (Arabic: تيمم‎) is the Islamic act of dry ablution using sand or dust, which may be performed in place of ritual washing (wudu or ghusl) if no clean water is readily available.

Tayammum may be substituted for wudu or ghusl when access to water is restricted or impractical, namely:

Tayammum consists of the following steps:

The same conditions that invalidate wudu also invalidate tayammum. In addition, a person's tayammum is invalidated as and when water becomes available.

Pierre Vogel (b. July 20, 1978 in Frechen), Islamic name Abu Hamza is a German Islamic preacher and a former professional boxer.

Vogel converted to Islam in 2001 and shortly thereafter began courses on Islamic studies in Germany. For two years he studied Arabic and the Quran at the private school Om Al-Qura in Mecca.^{[citation needed]}

In 2006 he returned to Berlin and started teaching Islam at the Al-Nur-Moschee mosque Neukölln, in universities and even among Christians.^{[citation needed]}

After 66 amateur fights^{[citation needed]} he turned professional at the age of 22, fighting briefly (for two years) as a cruiserweightfor the Sauerland club and was undefeated in seven bouts.

Vogel is married to a Muslim Moroccan woman and is father of three children.

He has been described in one German report as a "radical Muslim".

When he appeared at a Muslim meeting in Ferihegy^[when?], he said that polygamy is legitimate due to the fact that there are more women than men in Germany.

Shaykh Ahmad ibn Zayn al-Dín ibn Ibráhím al-Ahsá'í (Arabic: شيخ أحمد بن زين الدين بن إبراهيم الأحسائي‎) was (1753–1826) was the founder of a 19th century Shi`i school in the Persian and Ottoman empires, whose followers are known as Shaykhís.

He was a native of the Al-Ahsa region (Eastern Arabian Peninsula), educated in Bahrain and the theological centers of Najaf and Karbala in Iraq. Spending the last twenty years of his life in Iran, he received the protection and patronage of princes of the Qajar dynasty.

Little is documented about the early life of Shaykh Ahmad, except that he was born in Ahsa, in the northeast of the Arabian peninsula, to a Shi'i family of Sunni origin in either the year 1166 A.H. (1753 C.E.), or 1157 A.H. (1744 C.E.). Nabíl-i-A`zam, a Baha'i historian, documents his spiritual awakening in his book The Dawn-Breakers as follows:

While it is unclear how much of Nabil's interpretation is consistent with Shaykh Ahmad's true feelings, the underlying motivations for reform, and ultimately for messianic expectation, become somewhat clearer.