Hawzah News Agency – Imam Zayn al-Abidin peace be upon him says:

المؤمنُ يَصمُتُ لِيَسْلَمَ، ويَنْطِقُ لِيَغْنَم.

'The believer is silent in order that he remains safe, and speaks [only] in order to benefit.'

Source: al-Kafi, v. 1, p. 231, no. 3