Nasai

Explanation:
↰ The narrator of this hadith, Malik bin Numayr al-Khuza'i, is "Hasan al-Hadith" (of sound narration).
Imam Ibn Hibban rahimahullah has mentioned him in [الثقات : 386/5].
And Imam Ibn Khuzaymah rahimahullah [715] has authenticated the hadith narrated by him and thereby affirmed his reliability.

1272. Commentary: In the tashahhud (whether the first or the last), the right hand is placed from the very beginning in such a manner that three fingers and the thumb are closed, and the index finger remains open. This position is maintained until the takbir or the salam. The index finger can be kept straight and upright in a pointing manner from the beginning of the tashahhud to the end, without bending or moving it, or it can be moved continuously. Both methods are permissible and established. In fact, movement is a separate matter and pointing is another; therefore, mostly one should point (since the majority of narrations mention pointing), and occasionally, one may move it continuously, as has been detailed previously. See, the benefits and issues of Hadith: 890.

1275. Commentary: The verifier of the book has classified this narration as hasan (sound) in terms of its chain of transmission, while other scholars have declared the rest of the narration, except for «قَدْ أَحْنَاهَا شَيْئًا», to be sahih (authentic). Shaykh al-Albani rahimahullah has declared these words to be munkar (rejected), and the researchers of al-Mawsu‘ah al-Hadithiyyah have considered the rest of the narration, apart from these words, to be sahih li ghayrihi (authentic due to supporting evidence). Therefore, the mentioned narration, except for these words, is actionable. And Allah knows best. For further details, see: [ضعیف سنن أبي داود (مفصل) : 9/371 ، رقم : 176 ، والموسوعة الحدیثیة مسند الإمام أحمد : 25/200-201 ، رقم : 15866]

991. Commentary:
Shaykh al-Albani rahimahullah has declared this hadith to be weak; therefore, instead of bending the finger, it should be kept upright (i.e., during the Tashahhud).

Benefits and Issues:

➊ Pointing with the finger during the Tashahhud is Sunnah.

➋ The pointing should be done only with the finger of the right hand. (See: Hadith: 913)

➌ The manner of the hand while pointing will be mentioned in the following ahadith.