سورة الأنفال

Imam al-Rida (peace be upon him): The reason Mecca was named Mecca is that people used to whistle in it, and whoever went to Mecca they would say of him "maka", and this is the very saying of Allah the Mighty and Majestic: وَ ما کانَ صَلاتُهُمْ عِنْدَ الْبَیْتِ إِلَّا مُکاءً وَ تَصْدِیَةً [And their prayer before the House is nothing but whistling and clapping of hands]. So al-muka' means whistling, and al-tasdiya means clapping the hands.

Imam Sadiq (peace be upon him): Ibrahim ibn Umar al-Yamani, on the authority of one who narrated from Imam Sadiq (peace be upon him), said: The Imam, concerning the verse: وَ مَا کَانَ صَلاَتُهُمْ عِندَ الْبَیْتِ إِلاَّ مُکَاء وَ تَصْدِیَةً [And their prayer before the House is nothing but whistling and clapping of hands], said: "What is meant is whistling and clapping."

Ali ibn Ibrahim (may Allah have mercy on him): Quraysh agreed among themselves to attack the Prophet (peace be upon him and his family) by night and kill him. [After this agreement] they went to the Sacred Mosque and began whistling, clapping, and circumambulating the House of Allah. Concerning this Allah revealed the verse: وَ ما کانَ صَلاتُهُمْ عِنْدَ الْبَیْتِ إِلَّا مُکاءً وَ تَصْدِیَةً [And their prayer before the House is nothing but whistling and clapping of hands]. What is meant by muka' is whistling, and what is meant by tasdiyah is clapping. This verse is connected to the verse: [Remember] when the disbelievers were plotting against you (al-Anfal/30), even though it is placed after several verses.