Adam Clarke on 1 Peter 3:8

Be ye all of one mind - Unity, both in the family and in the Church, being essentially necessary to peace and salvation. See on Rom 12:16 (note); Rom 15:5 (note).

Having compassion - Συμπαθεις· Being sympathetic; feeling for each other; bearing each other's burdens.

Love as brethren - Φιλαδελφοι· Be lovers of the brethren.

Pitiful - Ευσπλαγχνοι· Tender-hearted; let your bowels yearn over the distressed and afflicted.

Courteous - Φιλοφρονες· Be friendly-minded; acquire and cultivate a friendly disposition. But instead of this word, ταπεινοφρονες, be humble-minded, is the reading of ABC, more than twenty others, with the Syriac, Arabic of Erpen, Coptic, Armenian, Slavonic, and some of the fathers. This is probably the true reading, and Griesbach has admitted it into the text.