Is prostration for forgetfulness (Sujud As-Sahw) required for one who joins a prayer late (Masbuq) and misses part of it?
Chapter on the Two Prostrations of Forgetfulness
Al-Mughni
Book of Prayer
Primary text
Prostration for forgetfulness is not obligatory for one who misses part of the prayer. This is the view held by the majority of scholars. It is also reported from Ibn Umar, Ibn Al-Zubayr, Abu Sa'id, 'Ata', Tawus, Mujahid, and Ishaq, concerning one who catches an odd number (Witr) of the Imam's prayer. The evidence for this is the statement of the Prophet, peace be upon him: "And what you miss, complete it," and in another narration, "Then make up for it." Neither narration commanded prostration, nor was this action reported [from the Prophet]. Furthermore, the Prophet, peace be upon him, missed part of a prayer while praying with 'Abd Al-Rahman ibn 'Awf, and he made up for it without performing prostration for forgetfulness, and this Hadith is agreed upon (Muttafaqun 'alayh).
Supporting text
A view exists that if one catches an odd number (Witr) of the Imam's prayer, they should prostrate for forgetfulness because they sit for the Tashahhud in a location other than its proper place.