It was narrated from Ka’b bin ‘Ujrah that the Messenger of Allah (ﷺ) saw a man who had interlocked his fingers during the prayer, so the Messenger of Allah (ﷺ) separated his fingers.
Hadith Referenceسنن ابن ماجه / كتاب إقامة الصلاة والسنة / 967
Hadith Gradingالألبانی:ضعيف | زبیر علی زئی:حسن
Hadith Takhrij«سنن الترمذی/الصلاة ( 386 )، ( تحفة الأشراف: 11121 )، وقد أخرجہ: مسند احمد ( 3/54، 4/242، 243 )، سنن الدارمی/الصلاة 121 ( 1445 ) ( ضعیف )» ( علقمہ اور ابو بکر بن عیاش کے ضعف کی وجہ سے یہ ضعیف ہے )
Narrated Kab ibn Ujrah: Abu Thumamah al-Hannat said that Kab ibn Ujrah met him while he was going to the mosque; one of the two (companions) met his companion (on his way to the mosque) And he met crossing the fingers of my both hands. He prohibited me to do so, and said: The Messenger of Allah ﷺ has said: If any of you performs ablution, and performs his ablution perfectly, and then goes out intending for the mosque, he should not cross the fingers of his hand because he is already in prayer.
Shaykh Umar Farooq Saeedi
562. Commentary: Imam Bukhari rahimahullah has presented ahadith in Sahih Bukhari «كتاب الصلوة باب تشبيك الأصابع فى المسجد» and elsewhere, from which the concession for this action is established. And the aforementioned hadith is also authentic. (Shaykh al-Albani rahimahullah)
The reconciliation and synthesis among them is that during the prayer or while proceeding towards the prayer specifically, this action is prohibited, and the prohibition is of a discouraging (tanzihi) nature, but not outside of that.
➋ While coming to the mosque, intertwining the fingers, cracking them, or other similar pointless actions—such as running, peeking here and there, idle talk, and laughing loudly—are in no way appropriate, because a person is, in effect, considered to be in prayer.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 562