عَنْ كَعْبِ بْنِ عُجْرَةَ رَضِيَ اللَّهُ عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ: ((لَا يَتَطَهَّرُ رَجُلٌ فِي بَيْتِهِ ثُمَّ يَخْرُجُ لَا يُرِيدُ إِلَّا الصَّلَاةَ إِلَّا كَانَ فِي صَلَاةٍ حَتَّى يَقْضِيَ صَلَاتَهُ، وَلَا يُخَالِفْ أَحَدُكُمْ بَيْنَ أَصَابِعِ يَدَيْهِ فِي الصَّلَاةِ))
It is narrated from Sayyiduna Ka'b bin 'Ujrah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Whoever performs ablution at home and then leaves (for the mosque) solely for the purpose of prayer, he remains in the state of prayer until he completes the prayer. And none of you should intertwine his fingers with each other during the prayer.