Speech has several roles across these narrations: encouraging learners, avoiding gratuitous abuse of useful creatures, refraining from angry judgments, and not ridiculing those who have died. In each case, how a person speaks can protect or injure others.
بَشِّرُوا is a positive instruction; لَا تَسُبُّوا is a prohibition; لَا يَقْضِيَنَّ strongly restrains a person who judges. The grammatical forms differ, but each promotes self-control and responsible treatment of others.