of worship. Salat means to call to the Lord Who created and gives life to the worshipper in Islam. This call realizes one to surrender caller's will, obeying his God. It is one of the Five Pillars of Islam. Islam gives concession conditionally if it is difficult to pray Salat in formal ways. People who find it physically difficult can perform Salat in a way suitable to them. To perform valid Salat, Muslims must be in a state of ritual purity, which is mainly achieved by ritual wash ups, (wuḍūʾ), as per prescribed procedures. Salat consists of "standing" (Qiyam) intending to call God, bow at knees (Ruku) meaning to ready to obey, prostrate (Sajda) willing to surrender worshipper's will to God's, then to sit (Tashhud) asserting evidence of the oneness of God and the finality of God's apostle (Nabi). Sawm In the terminology of Islamic law, sawm means to abstain from eating, drinking (including water) and sexual intercourse from dawn until dusk. The observance of sawm during the holy month of Ramadan is one of the Five Pillars of Islam, but is not confined to that month. Zakat Zakat is the practice of charitable giving by Muslims based on accumulated wealth and is obligatory for all who are able to do so. It is considered to be a personal responsibility for Muslims to ease economic hardship for others and eliminate inequality. Hajj The Hajj is an Islamic pilgrimage to Mecca and the largest gathering of Muslims in the world every year. It is one of the five pillars of Islam, and a religious duty which must be carried out by every able-bodied Muslim who can afford to do so at least once in his or her lifetime. Other tenets In addition, some Muslims include Jihad and Dawah as part of aqidah Jihad Jihad (to struggle) and literally means to endeavor, strive, labor to apply oneself, to concentrate, to work hard, to accomplish. It could be used to refer to those who physically, mentally or economically serve in the way of God. Dawah Da‘wah ("invitation") means the proselytizing or preaching of Islam. Da‘wah literally means "issuing a summon" or "making an invitation," being an active participle of a verb meaning variously "to summon" or "to invite." A Muslim who practices da‘wah, either as a religious worker or in a volunteer community effort, is called a dā‘ī (داعي plural du‘āh, gen: du‘āt