If, however, a person setteth about speaking well of another, opening his lips to praise another, he will touch an answering chord in his hearers and they will be stirred up by the breathings of God. Their hearts and souls will rejoice to know that, God be thanked, here is a soul in the Faith who is a focus of human perfections, a very embodiment of the bounties of the Lord, one whose tongue is eloquent, and whose face shineth, in whatever gathering he may be, one who hath victory upon his brow, and who is a being sustained by the sweet savours of God. Now which is the better way? I swear this by the beauty of the Lord: whensoever I hear good of the friends, my heart filleth up with joy; but whensoever I find even a hint that they are on bad terms one with another, I am overwhelmed by grief. Such is the condition of ‘Abdu’l-Bahá. Then judge from this where your duty lieth.
(‘Abdu’l-Bahá, Selections from the Writings of ‘Abdu’l-Bahá, p. 231)
Never speak disparagingly of others, but praise without distinction.
(‘Abdu’l-Bahá, The Promulgation of Universal Peace, p. 453)