Kindness, in the text
Three reports on gentleness, and one verse worth putting beside them. A kind word and forgiveness are better than charity followed by injury. And gentleness does not enter a thing without adorning it, nor leave it without spoiling it.
Qur’an and Sunnah
۞قَوۡلࣱ مَّعۡرُوفࣱ وَمَغۡفِرَةٌ خَيۡرࣱ مِّن صَدَقَةࣲ يَتۡبَعُهَآ أَذࣰ ىۗ وَٱللَّهُ غَنِيٌّ حَلِيمࣱ
A kind word and forgiveness is better than a charitable deed followed by hurtful [words]: God is self-sufficient, forbearing
Qur’an 2:263
Jarir reported from Allah's Messenger (ﷺ):He who is deprived of tenderly feelings is in fact deprived of good
Sahih Muslim 2592graded sound, sahihaynfull report
A'isha, the wife of Allah's Apostle (ﷺ), reported that Allah's Messenger (ﷺ) said:'A'isha, verily Allah is kind and He loves kindness and confers upon kindness which he does not confer upon severity and does not confer upon anything else besides it (kindness)
Sahih Muslim 2593graded sound, sahihaynfull report
A'isha, the wife of Allah's Apostle (ﷺ), reported Allah's Apostle (ﷺ) as saying:Kindness is not to be found in anything but that it adds to its beauty and it is not withdrawn from anything but it makes it defective
Sahih Muslim 2594graded sound, sahihaynfull report
Translation: M.A.S. Abdel Haleem, The Qur'an, Oxford University Press, 2004.