“The Messenger of Allah ﷺ, Abu Bakr and ‘Umar did not give us so much leeway in anything as they did with regard to the prayer for the deceased,” meaning that there was nothing affixed.
مَا أَبَاحَ لَنَا رَسُولُ اللَّهِ ﷺ وَلاَ أَبُو بَكْرٍ وَلاَ عُمَرُ فِي شَىْءٍ مَا أَبَاحُوا فِي الصَّلاَةِ عَلَى الْمَيِّتِ يَعْنِي لَمْ يُوَقِّتْ