قَامَ بِهِ لَا وَقَعَ عَلَيْهِ — Translation: “the action proceeds from it, rather than falling upon it.”
This is the core distinction between the fāʿil and the object. In ضَرَبَ زَيْدٌ عَمْرًا, the striking proceeds from Zayd, so زَيْدٌ is the fāʿil; it falls upon ʿAmr, so عَمْرًا is the direct object. Merely appearing after a verb does not make a noun the fāʿil.
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Al-Marfūʿāt: The Fāʿil, Its Definition and Full Parsing
قَامَ بِهِ لَا وَقَعَ عَلَيْهِ — Translation: “the action proceeds from it, rather than falling upon it.”
This is the core distinction between the fāʿil and the object. In ضَرَبَ زَيْدٌ عَمْرًا, the striking proceeds from Zayd, so زَيْدٌ is the fāʿil; it falls upon ʿAmr, so عَمْرًا is the direct object. Merely appearing after a verb does not make a noun the fāʿil.