عَنْ أَبِي مَالِكٍ الْأَشْعَرِيِّ رَضِيَ اللَّهُ عَنْهُ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَنَّهُ كَانَ يُسَوِّي بَيْنَ الْأَرْبَعِ رَكَعَاتٍ فِي الْقِرَاءَةِ وَالْقِيَامِ، وَيَجْعَلُ الرَّكْعَةَ الْأُولَى هِيَ أَطْوَلُهُنَّ لِكَيْ يَثُوبَ النَّاسُ، وَيَجْعَلُ الرِّجَالَ قُدَّامَ الْغِلْمَانِ، وَالْغِلْمَانَ خَلْفَهُمْ وَالنِّسَاءَ خَلْفَ الْغِلْمَانِ، وَيُكَبِّرُ كُلَّمَا سَجَدَ وَكُلَّمَا رَفَعَ، وَيُكَبِّرُ كُلَّمَا نَهَضَ بَيْنَ الرَّكْعَتَيْنِ إِذَا كَانَ جَالِسًا
It is narrated from Sayyiduna Abu Malik Ash'ari (may Allah be pleased with him) that the recitation and standing in all four rak'ahs of the Messenger of Allah (peace and blessings be upon him and his family) were equal, except that he would prolong the first rak'ah so that people could arrive. The Prophet (peace and blessings be upon him and his family) would make the men stand in front of the children, the children behind them, and the women behind the children. Whenever he (peace and blessings be upon him and his family) performed sajdah and rose from it, he would say takbeer. Similarly, when after two rak'ahs he sat for tashahhud and then stood up for the third rak'ah, he would say Allahu Akbar.