The duration that obligates the traveler to complete the prayer by virtue of the intention to reside there is what is more than twenty-one prayers. This was narrated by Al-Athram, Al-Marrudhi, and others. Another report from him states that if he intends to reside for four days, he completes [the prayer], and if he intends less than that, he shortens it. This is the view of Malik, Al-Shafi'i, and Abu Thawr; because three is the limit of a small amount, based on the evidence of the Prophet's (may Allah bless him and grant him peace) statement: "The emigrant stays for three [days] after finishing his ritual [pilgrimage]." When Umar (may Allah be pleased with him) cleared out the People of the Covenant (Ahl al-Dhimmah), he set a limit of three [days] for those who came among them as merchants. This indicates that three is within the ruling of travel, and what exceeds it is within the ruling of residency. This view is also reported from Uthman (may Allah be pleased with him). Al-Thawri and the People of Opinion (Ashab al-Ra'y) said: If he resides for fifteen days, including the day he leaves, he completes it, and if he intends less than that, he shortens it. This is reported from Ibn Umar, Sa'id ibn Jubayr, and Al-Layth ibn Sa'd, due to what is narrated from Ibn Umar and Ibn Abbas that they both said: "If you arrive and intend to stay in it for fifteen nights, then complete the prayer." There is no known dissenter to them. A similar view is reported from Sa'id ibn al-Musayyib. Qatadah narrated from him, saying: "If you stay for four [days], then pray four [rak'ahs]." It is also reported from Ali (may Allah be pleased with him) that he said: "The one who resides for ten [days] completes the prayer, and the one who says 'I will leave today, I will leave tomorrow' for a month shortens the prayer." This is the view of Muhammad ibn Ali, his son, and Al-Hasan ibn Salih. From Ibn Abbas, he said: "If you arrive..."