His fast is correct. However, it is befitting for the fasting person to spend his fast indulged in obedience: prayer, reading the Qur’aan, remembrance [of Allah], and other than these things.
As it relates to frivolous speech, then this is a loss for a person, rather he is fasting or not. This is due to the statement of the Prophet, prayers and peace upon him, ‘Whoever believes in Allah and the last day, let him say good things or be quiet.’ [al-Bukhaaree and Muslim]
Frivolous speech sometimes turns into speech that is impermissible, such as backbiting or belittling a person, and what resembles these things. Thus, it is befitting for the intelligent person to protect his tongue from everything that there is no benefit in, whether he is fasting or not. (1)
(1): Muhammad al-‘Uthaymeen, Fataawaa Noor ‘ala ad-Darb, v.7/pg.182/#2771
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