Al-Sha’bi reported: Umar ibn al-Khattab, may Allah be pleased with him, said, “Fasting is not merely from food and drink alone. Rather, it is from lies, falsehood, vain talk, and swearing.”
Source: Muṣannaf Ibn Abī Shaybah 8882
عَنْ الشَّعْبِيِّ قَالَ قَالَ عُمَرُ رضي الله عنه لَيْسَ الصِّيَامُ مِنْ الطَّعَامِ وَالشَّرَابِ وَحْدَهُ وَلَكِنَّهُ مِنْ الْكَذِبِ وَالْبَاطِلِ وَاللَّغْوِ وَالْحَلِفِ
8882 مصنف ابن أبي شيبة كتاب الصيام ما يؤمر به الصائم من قلة الكلام