Explain the function of 'al-isti'ara al-makniyya' (الاستعارة المكنية) and how it differs from 'al-isti'ara al-tasrihiyya' (الاستعارة التصريحية).

'Al-isti'ara al-makniyya' (الاستعارة المكنية), or 'implied metaphor', and 'al-isti'ara al-tasrihiyya' (الاستعارة التصريحية), or 'explicit metaphor', are two types of 'isti'ara' (استعارة - metaphor) in Arabic rhetoric. A metaphor, in general, is a figure of speech that involves an implicit comparison between two unlike things. The key difference lies in *how the comparison is presented*. In 'al-isti'ara al-makniyya', the *thing being compared (the 'musta'ar lahu' - المستعار له) is not explicitly mentioned*. Instead, only a characteristic or attribute associated with it is used to describe the other thing (the 'musta'ar minhu' - المستعار منه). This creates an implied comparison, where the reader must infer the missing element. For example, in the sentence 'ابتسم النهار' (ibtasama al-naharu - the day smiled), the day (النهار) is being described as if it were a person capable of smiling. However, the person is not mentioned explicitly; only the act of smiling, an attribute of a person, is used. This implies a comparison between the day and a person, suggesting that the day is bright, cheerful, or welcoming. In 'al-isti'ara al-tasrihiyya', on the other hand, the *thing being compared (the 'musta'ar lahu') is explicitly mentioned*, while the word that would normally be used to describe it is replaced by a word that belongs to the other thing (the 'musta'ar minhu'). This creates a direct and explicit comparison. For example, in the sentence 'رأيت أسدًا يخطب' (ra'aytu asadan yakhtubu - I saw a lion giving a speech), the word 'lion' (أسدًا) is used to refer to a brave and eloquent speaker. The speaker is explicitly mentioned, but the word 'speaker' is replaced by 'lion', creating a direct comparison. The lion is used metaphorically to convey the speaker's qualities of courage and eloquence. Therefore, 'al-isti'ara al-makniyya' creates an *implied and indirectcomparison*, while 'al-isti'ara al-tasrihiyya' creates an *explicit and directcomparison*. The former relies on suggestion and inference, while the latter relies on direct substitution.