Yes, of course, the Holy Qur’an and the Hadeeths have many instructions
about the discipline of speech.

1)    In Surah 2 : verse 83 Allah (SWT) says : “And speak good to
people”. Which means that the freedom of speech should not harm the
interest or respect of others.

2)    In Surah Israa' (Bani Israel) : verse 53 Allah (SWT) says : “And
tell my servants to speak in the best way because Shaitan verily tries
to create conflict among them. Surely Shaitan is the clear enemy of
man”.

3)    In Surah 41 : verse 34 Allah (SWT) says : “The good deeds are
never equal to the bad deeds. Repel the evil with the better one”.
Which means that we must avoid talking any bad with the excuse of
freedom of speech.

4)    In Surah 16 : verse 125 Allah (SWT) says : “Invite and call
people to the way of your Lord with wisdom and for preaching and have
debate with them in better way which means that we should keep fair
discipline for the freedom of speech.

In Hadith we have:

1)    Talk to people in the best way that you like them to talk to you
(Imam Mohammed al-Baqir (AS) in Tafseer al-Ayyashi vol 1 pg 48).

2)    Hadith in al-Kafi, vol 2 pg 63, from Imam Ja’far as-sadiq (AS)
that he (AS)  said: He is not from us who is not a good companion and
a good friend and who has not good morals with them.

3)    “Deal with people as you want them to deal with you and talk to
them as you want them to talk to you” (Jaami' Ahadeeth Al-Shia)

Wassalam.