“The Messenger of Allah ﷺ said: ‘Allah and His angels send blessings upon those who complete the rows, and whoever fills a gap, Allah will raise him one degree in status thereby.’” (Using translation from Ibn Mājah 995)
قَالَ رَسُولُ اللهِ ﷺ إِنَّ اللهَ ﷻ وَمَلَائِكَتَهُ عَلَيْهِمُ السَّلَام يُصَلُّونَ عَلَى الَّذِينَ يَصِلُونَ الصُّفُوفَ وَمَنْ سَدَّ فُرْجَةً رَفَعَهُ اللهُ بِهَا دَرَجَةً