﴿ وَٱلَّذِينَ يَصِلُونَ مَآ أَمَرَ ٱللَّهُ بِهِۦٓ أَن يُوصَلَ وَيَخْشَوْنَ رَبَّهُمْ وَيَخَافُونَ سُوٓءَ ٱلْحِسَابِ ﴾

“and who keep together what God has bidden to be joined, and stand in awe of their Sustainer and fear the most evil reckoning [which awaits such as do not respond to Him];”

Please check ayah 13:24 for complete tafsir.