The miswak (miswaak, siwak, sewak, السواك) is a teeth cleaning twig made from a twig of the Salvadora persica tree (known as arak in Arabic). It has a long, well-documented history and is reputed for its medicinal benefits. It also features prominently in Islamic hygienical jurisprudence.

The miswak is predominant in Muslim-inhabited areas, but its use predates the inception of Islam. The stick's use has spread from the Middle East to South and Southeast Asia, where it is known as Kayu Sugi (Malay for 'chewing stick'). It is often mentioned that the Islamic Prophet Muhammad recommended its use. He is quoted in various Hadith extolling the twig's virtues:

A 2003 scientific study comparing the use of miswak with ordinary toothbrushes concluded that the results clearly were in favor of the users who had been using the miswak, provided they had been given proper instruction in how to brush using it. The World Health Organization (WHO) recommended the use of the miswak in 1986 and in 2000 an international consensus report on oral hygiene concluded that further research was needed to document the effect of the miswak.

Zakir Abdul Karim Naik (Urdu: ذاکر عبدالکریم نائیک; born 18 October 1965) is an Indian public speaker on the subject of Islam and comparative religion. He is the founder and president of the Islamic Research Foundation (IRF), a non-profit organisation that owns the Peace TV channel based in Dubai, UAE. He is sometimes referred to as a televangelist. Before becoming a public speaker, he trained as a doctor. He has written two booklets on Islam and comparative religion. He is regarded as an exponent of the Salafi ideology; he places a strong emphasis on individual scholarship and the rejection of "blind Taqlid", which has led him to repudiate the relevance of sectarian or Madh'hab designations, all the while reaffirming their importance.

Zakir Abdul Karim Naik was born on 18 October 1965 in Mumbai, India. He attended St. Peter's High School in Mumbai. Later he enrolled at Kishinchand Chellaram College, before studying medicine at Topiwala National Medical College and Nair Hospital and later the University of Mumbai, where he obtained a Bachelor of Medicine and Surgery (MBBS). His wife, Farhat Naik, works for the women's section of the IRF.