for He stipulated, saying: "Then he is" (the one who did) this "of those who have believed and enjoined upon each other patience" regarding what Allah has commanded them and what He has forbidden them, "and enjoined upon each other compassion" through showing mercy among themselves.
Muhammad said: "Then" here is in the meaning of "and."
فَاشْترط فَقَالَ: ﴿ثمَّ كَانَ﴾ (الَّذِي فَعَلَ) هَذَا ﴿مِنَ الَّذِينَ آمنُوا وَتَوَاصَوْا بِالصبرِ﴾ عَلَى مَا أَمَرَهُمُ اللَّهُ بِهِ وَعَمَّا نَهَاهُمْ عَنْهُ ﴿وَتَوَاصَوْا بِالْمَرْحَمَةِ﴾ بِالتَّرَاحُمِ فِيمَا بَيْنَهُمْ.
قَالَ مُحَمَّدٌ: (ثمَّ) هَاهُنَا فِي معنى الْوَاو.